AUTOPILOT Installation Manual Rev. 2.1

Autopilot – Kanardia

Manuals – Kanardia

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Autopilot-Installation-ManualRev2.1

Autopilot -- Installation Manual
Kanardia d.o.o. November 2020
Revision 2.1

Autopilot Installation Manual

Contact Information
Publisher and producer: Kanardia d.o.o. Lopata 24a SI-3000 Slovenia
Tel: +386 40 190 951 Email: info@kanardia.eu
A lot of useful and recent information can be also found on the Internet. See http://www.kanardia.eu for more details.

Copyright
This document is published under the Creative Commons, Attribution-ShareAlike 3.0 Unported licence. Full license is available on http://creativecommons. org/licenses/by-sa/3.0/legalcode web page and a bit more human readable summary is given on http://creativecommons.org/licenses/by-sa/3.0/. In short, the license gives you right to copy, reproduce and modify this document if:
you cite Kanardia d.o.o. as the author of the original work,
you distribute the resulting work only under the same or similar license to this one.

Credits
This document was written using TeX Live (LATEX) based document creation system using Kile running on Linux operating system. Most of the figures were drawn using Open Office Draw, Inkscape and QCad applications. Photos and scanned material was processed using Gimp. All document sources are freely available on request under the licence mentioned above and can be obtained by email. Please send requests to info@kanardia.eu.

Revision History
The following table shows the revision history of this document.

Autopilot Installation Manual

Revision 1.0 1.1 1.2 2.0 2.1

Date Aug 2015 Maj 2016 Jul 2016 Feb 2020 Nov 2020

Description Initial release. Tuning notes were added. Tuning table expanded. Complete Manual rework. Updated for changes in software version 3.8, Amigo and Nesis/Aetos windows.

Autopilot Installation Manual

CONTENTS

Contents

1 Introduction

1.1 Designations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.2 Intended Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.3 Operation Limitations . . . . . . . . . . . . . . . . . . . . . . . 9

1.4 Minimal Configuration . . . . . . . . . . . . . . . . . . . . . . . 9

1.4.1 Nesis/Aetos Based Minimal System . . . . . . . . . . . 10

1.4.2 Horis/Emsis Based Minimal System . . . . . . . . . . . 10

1.5 Principle of Operation . . . . . . . . . . . . . . . . . . . . . . . 11

2 Mechanical Installation

2.1 Servo Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.2 Servo Arm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.3 Servo Arm Limiter . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.4 Servo Arm Safety Pin . . . . . . . . . . . . . . . . . . . . . . . 14

3 Electrical Installation

3.1 Electrical Power . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2 CAN Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.3 External Push Button . . . . . . . . . . . . . . . . . . . . . . . 15

3.3.1 Autopilot Quick Disconnect . . . . . . . . . . . . . . . . 16

3.3.2 Autopilot Level . . . . . . . . . . . . . . . . . . . . . . . 16

3.4 Joyu Command Stick . . . . . . . . . . . . . . . . . . . . . . . . 16

4 Configuration

4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.2 Autopilot Settings . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.2.1 Servo Configuration . . . . . . . . . . . . . . . . . . . . 18

4.2.2 Ground Test . . . . . . . . . . . . . . . . . . . . . . . . 20

4.2.3 Operation Limits . . . . . . . . . . . . . . . . . . . . . . 21

4.2.4 Controller Parameters . . . . . . . . . . . . . . . . . . . 23

4.2.5 Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Autopilot Installation Manual

CONTENTS

5 Tuning

5.1 Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.1.1 PID controller . . . . . . . . . . . . . . . . . . . . . . . 26

5.2 Step Change and Response . . . . . . . . . . . . . . . . . . . . 27

5.3 Cascade Controller . . . . . . . . . . . . . . . . . . . . . . . . . 28

5.4 Controller Problems . . . . . . . . . . . . . . . . . . . . . . . . 28

5.4.1 Backlash . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.4.2 Slip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.5 Tuning Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.5.1 On-Ground . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.5.2 In-Flight . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

5.6 Tuning Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

6 In-Flight Tuning

6.1 Elevator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6.1.1 Pitch tuning . . . . . . . . . . . . . . . . . . . . . . . . 32

6.1.2 Vertical speed tune . . . . . . . . . . . . . . . . . . . . . 36

6.2 Aileron tune . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

6.2.1 Roll tune . . . . . . . . . . . . . . . . . . . . . . . . . . 39

6.2.2 Heading tune . . . . . . . . . . . . . . . . . . . . . . . . 40

6.3 Fine tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

6.3.1 Roll feed forward . . . . . . . . . . . . . . . . . . . . . . 41

6.3.2 Motor power . . . . . . . . . . . . . . . . . . . . . . . . 42

7 Quick Configuration

7.1 Configure Servos . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7.2 Direction Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7.3 Operating Limits . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7.4 Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

8 Safety Measures

8.1 Automatic Disable . . . . . . . . . . . . . . . . . . . . . . . . . 45

8.2 Manual Disable . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

8.3 Electrical Disable . . . . . . . . . . . . . . . . . . . . . . . . . . 46

8.4 Mechanical Disable . . . . . . . . . . . . . . . . . . . . . . . . . 46

Autopilot Installation Manual

CONTENTS

A Autopilot Installation And Tuning Form

B Parameters For Known Airplanes

B.1 Ekolot Topaz . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

B.2 Pipistrel Sinus . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

B.3 Aeropilot Legend 540 . . . . . . . . . . . . . . . . . . . . . . . . 49

B.4 Evector Eurostar EV97 . . . . . . . . . . . . . . . . . . . . . . 49

B.5 Aerospool Dynamic WT9 . . . . . . . . . . . . . . . . . . . . . 50

B.6 Roko Aviation . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

B.7 Aeroprakt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

B.8 Direct Fly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

B.9 Comco Ikarus . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Autopilot Installation Manual

1. Introduction

1 Introduction
First of all, we would like to thank you for purchasing our product. This chapter describes the basic principle on which autopilot operates. After reading it, you will be familiar with basic knowledge you will need to properly install and tune the autopilot.

CAUTION: The autopilot is not TSO approved as a flight instrument.

1.1 Designations
A few icons appear on the side of the manual, which have special meanings: This icon denotes information that needs to be taken with special attention. This icon denotes background information about the subject.
This icon denotes a tip.
In the text, Shall & Should appear frequently.
Shall . . . the use of this term indicates a requirement! Should . . . the use of this term indicates a characteristics that is not required,
but it is highly recommended.

1.2 Intended Use

The autopilot is designed to help a pilot in stable, controllable flight conditions during cruising. If such conditions are met, the autopilot can be engaged to take some relief from the pilot, who can perhaps focus a bit more on ATC communication or to do some navigation task. Nevertheless, it is still pilot's responsibility to monitor the autopilot and airplane behavior all the time.

Autopilot Installation Manual

1.3 Operation Limitations

1.3 Operation Limitations
Always respect the following limitations.
The autopilot shall be only used in VFR (Visual Flying Rules) conditions.
Information from the Aircraft Operating Handbook always supersedes information given in this manual.
The autopilot is designed to be used only in cruising conditions. It will not work at low and high speeds. It can't fly approaches and departures and it can't do takeoffs and landings.
The autopilot shall not be used in turbulence.
Do not use the autopilot with flaps extended.
In any case of abnormal activity, the autopilot must be deactivated and the pilot must take over the commands immediately. Never wait for autopilot to deactivate itself automatically.
Autopilot does not use any information from Magu (magnetic compass).

1.4 Minimal Configuration
Most modern light airplanes can be controlled during a stable flight by controlling elevator and aileron only. An autopilot function can be achieved using the following minimum configuration:

Two servo motors that are mechanically connected with the airplane command system. One motor controls elevator and the other controls aileron.
An AD-AHRS-GPS device which consists of many sensors and provides crucial information required by the autopilot system (airspeed, rate of climb, pitch, roll, position, direction, altitude, etc.) Such device is inside one of our PDF instruments, for example, Nesis PFD, Aetos PFD, Horis PFD or Emsis PFD.
A display unit takes pilot inputs like required altitude and direction. It is also used to enter configuration parameters required to properly setup the autopilot system.

Autopilot Installation Manual

1.4 Minimal Configuration

A servo motor controller. It monitors the pilot instructions and information obtained from the sensors and controls the servo motor accordingly.
A communication system that connects all devices and allow information exchange in real time.
In Kanardia autopilot case, there are two different solutions for an autopilot minimal system.

1.4.1 Nesis/Aetos Based Minimal System
When Nesis or Aetos is used as a base, the following minimal equipment is required for a fully functional autopilot:
Two SERU servo motors. SERU consists of a servo motor and an integrated controlling unit, which serves as a motor driver. One SERU controls elevator and the other controls aileron.
Nesis III (or Aetos) PFD. The display has integrated AD-AHRS-GPS device, which provides all sensor data. The display has several buttons and a knob that allow pilot control over the system. In addition, touch screen can be also used on Nesis III.
Simple RJ45 cables (a.k.a. Ethernet cables) are needed to connect them together. The devices are communicating using the CAN bus system, which is integral part of almost all Kanardia devices.
In this combination Amigo is optional, but recomended nevertheless.

1.4.2 Horis/Emsis Based Minimal System
When Horis or Emsis is used as a base, the following minimal equipment is required for a functional autopilot:

Two SERU servo motors. SERU consists of a servo motor and an integrated controlling unit, which serves as a motor driver. One SERU controls elevator and the other controls aileron.
Horis 80/57 (or Emsis 80/3.5") PFD unit with integrated AD-AHRSGPS device, which provides all sensor data.
Amigo display, which acts as a command panel for the autopilot.

Autopilot Installation Manual

1.5 Principle of Operation

Simple RJ45 cables (a.k.a. Ethernet cables) are needed to connect them together. The devices are communicating using the CAN bus system, which is integral part of almost all Kanardia devices.
In this combination, Amigo is essential.
1.5 Principle of Operation
When autopilot is active, pilot selects requested altitude, direction and rate of climb or descend. AD-AHRS-GPS device provides current values for almost all flight parameters. Controller units compare the requested values with actual values and give appropriate commands to the servo motors. The PID controller principle is used together with the cascade control system.
The autopilot drives two separate controls: aileron and elevator. In general these two controls are independent, though minor dependency may exists. Each control has two control loops1. Elevator control has pitch loop and vertical speed loop. The two loops are regulated by cascade. This means that requested altitude sets wanted vertical speed and the vertical speed loop sets wanted pitch. The pitch loop then controls the elevator by minimizing the difference between requested and actual pitch. Aileron works in a similar way. Requested direction sets the required roll angle and the roll loop controls the aileron trying to minimize the difference between requested and actual roll angle.
This means that autopilot has four loops: pitch and vertical speed loops are used for elevator, while heading and roll loops are used for aileron. All these loops must be properly tuned to achieve requested autopilot operation. Various experimental values in the form of tuning parameters are provided at the end of the document. These values represent good starting point for first autopilot tests.

2 Mechanical Installation

This section provides information about the installation of autopilot servo motors (the SERU device) into an airplane. It contains important rules which

1 The control loop is basic term from control theory. In simple terms the control loop tries to move the actuator in such a way that difference between WANTED and ACTUAL value becomes minimal.

Autopilot Installation Manual

2.1 Servo Motor

must be obeyed to have a working and safe autopilot system. The installation information in this section is extremely important and must be clearly understood by the installer.
Improper servo installation or failure to observe and diagnose installation problems prior to flight can result in extremely serious consequences, including loss of ability to control the aircraft. If there are any questions on the part of the installer it is mandatory to resolve these questions prior to flight of the aircraft.

CAUTION: Improper installation could result in lost aircraft controls, injury or death!

2.1 Servo Motor
The servo motor must be installed in a fixed position. It must be attached with all four mounting screws. The motor mount should be provided by aircraft manufacturer and has to be adapted to specific airplane model. The motor should be oriented parallel with longer edge regarding control rod connected to the servo arm. The servo schematics is given in Figure 1. It defines three important elements:
O1 Safety pin, O2 Arm movement limiter, O3 Arm.

1 2

Figure 1: Safety pin, limiter and arm.

Autopilot Installation Manual

2.2 Servo Arm

2.2 Servo Arm
Servo arm has multiple holes for mounting control rod. The hole in use should be chosen to maximize the arm rotation. Servo arm should not be removed or replaced without Kanarida advise. The removal of servo arm includes removal of safety pin. Please contact Kanarida before replacing safety pin for latest instructions.

Extreme command position 90° is ideal case for

30° or more!

neutral command position

Extreme command position 150° or less!

Figure 2: Main servo dimensions.

Figure 2 illustrates valid relative positions between command rod and servo arm. When command is in neutral position, the angle between rod and arm shall be 90 or at least very close to this ideal case. When command is in its extreme position the angle between the command rod and the arm must never be more than 150 or less then 30.
Under no circumstances the servo arm is allowed to come into position called over center the position at which the primary aircraft control would lock up and can result in fatal crash. A mechanical stops must be applied to prevent this to happening. Mechanical stops must limit the arm movement at least 30 before the over center situation.

2.3 Servo Arm Limiter

To protect against control lock up, a mechanical arm limiter is supplied with servo. The limiter is drilled so that it can be mounted at different angles as required (18 intervals).
The limiter must not prevent aircraft command movements. Always make sure that the controls can have their full travel and they never reach the servo limiter.

Autopilot Installation Manual

2.4 Servo Arm Safety Pin

2.4 Servo Arm Safety Pin
Safety pin is a safety mechanism which prevents blocking of the aircraft command system for the case of blocked servo motor. If servo blocks the command system, pilot must apply high force on the command stick. This force will break the pin and release the servo from command system. Once the pin is broken, the autopilot system is not operational until the pin is replaced. If safety pin is broken or it gets slack the whole autopilot system must be checked. Only after the cause of the problem was found and corrected, safety pin can be replaced with a new pin. Always use original safety pin. The safety pin is made from high grade steel and it is intentionally weaken to break at specific torque applied on servo arm. The airplane command system must be capable to withstand the forces in the command system required to break the safety pin.
3 Electrical Installation
Servo motor has two electrical connections. The first one provides power for the electrical motor and the second one connects controlling device with the CAN bus. (The controlling device is hidden inside the servo motor).
3.1 Electrical Power
The autopilot servo motor must be connected to a 12 V DC standard aircraft power source. It is also possible to use 24 V DC power. The maximum current consumption for one servo motor is 1.5 A (at 12 V). Always protect servos with an automatic/replaceable fuse and a switch. The fuse protects against over-current and the switch allows quick disconnect by taking power from the motor. Figure 3 shows typical connection.

Autopilot switch Fuse 5A
+12V Ground
Figure 3: Typical connection of servo motor electrical power.

Autopilot Installation Manual

3.2 CAN Bus

The autopilot switch must be easily accessible by the pilot. The pilot must be able to reach it in any moment.
3.2 CAN Bus
Servo motor must also be connected to the CAN bus. The controller module is built in the servo housing. The controller exchanges the information over the CAN bus. In addition, CAN bus is also used to power the controller. This means that controller works even when servo motors are without power. Figure 4 shows CAN bus connections for the minimal autopilot configuration. In reality more devices can be connected to the CAN bus. The CAN bus goes trough Nesis or Aetos, where it is internally connected to AD-AHRS-GPS module. On the servo side, T junction is needed and a short connection is made from T to the servo controller.
Nesis III or Aetos
Airu AD-AHRS-GPS

to other devices

CAN bus T
Ctrl

to other devices T
Ctrl

Figure 4: Typical CAN bus connection for Nesis/Aetos based minimal autopilot configuration.

Please note that CAN bus must be terminated with a 120 Ohm terminator on both ends of the main line. Terminators are not shown on Figure 4.

3.3 External Push Button

It is advisable to install an external push button, which allows for quick autopilot disconnect and level commands. The push button shall be installed on the command stick, where it is easily accessed by pilot. Two wires from

Autopilot Installation Manual

3.4 Joyu Command Stick

the push button must be connected to the Nesis/Aetos service port or to Amigo auxiliary port. The connection details are given in the Nesis/Aetos installation or in Amigo manual, see the External Push Button section.
3.3.1 Autopilot Quick Disconnect
Nesis/Aetos must be then configured to react on the push button event. When the button is pushed, the autopilot disconnect command is sent via CAN bus to both servo controllers, which will cut power of both servo motors. In the case of Amigo, no configuration is necessary.
3.3.2 Autopilot Level
The same button can be used also used for the autopilot level command. This command will activate Track Hold mode for aileron and Altitude Hold mode for elevator. In the case of Nesis/Aetos, this function must be configured. In the case of Amigo, it is activated by a long press on the external button. No configuration is necessary.
3.4 Joyu Command Stick
Alternatively, Joyu command stick can be also used. Joyu has multiple programmable buttons and one or more of its buttons can be assigned to operate the autopilot. Short press on the button should be used for autopilot disconnect and long press for the autopilot level function. Please see the Joyu manual for more details.

4 Configuration

For the autopilot to operate properly, controllers inside the servo motors must be configured. Once the configuration is complete, the whole system must be also tuned. In general, tuning is needed for every airplane. In most cases airplanes of the same type may use the same autopilot configuration if autopilot mechanical installation is identical.
Any accidental change of any of parameters in this section and subsections may result of autopilot being inoperative.

Autopilot Installation Manual

4.1 Overview

4.1 Overview
These configuration and tuning can be done either with Nesis/Aetos or with Amigo. This section includes several figures. Each figure illustrates Nesis/Aetos solution on the left and Amigo solution in the right. If you have both Nesis/Aetos and Amigo, do not use the Autopilot configuration or tuning on both instruments at the same time. Use either Nesis/Aetos or Amigo. Next steps reveal typical workflow:
1. Configure both servos. Each servo has several parameters that must be set properly. Its function (what it moves ailerons or elevator) and movement direction are two examples.
2. Ground test is performed. It tells weather servos are moving commands (elevator and ailerons) in correct directions.
3. Autopilot operation limits are set. They define an envelope of values, which must be met for AP to operate. This is a very important safety feature.
4. Autopilot controller parameters are set. Most of them can be set on the ground, but some must be adjusted during flight tests.
5. Autopilot is tuned, which is the most difficult part. This can be performed only in flight. Several controller values must be determined.
First three steps shall be set on the ground. Most of the fourth step can be also set on the ground, but may be necessary to change some of parameters during the flight test. Final step can be only done in flight. Section 7 reveals the workflow for airplanes where autopilot parameters are already known.

4.2 Autopilot Settings

Please refer also to the Nesis/Aetos or Amigo manual.
In Nesis/Aetos, the settings are accessible from Service options page in the display. Special password (provided with the instrument) must be entered to access the Service options page. The password can be also found under the Info icon.

Autopilot Installation Manual

4.2 Autopilot Settings

In Amigo, press and hold the ALT knob and then select the Autopilot from the menu.
Figure 5 shows the main autopilot settings menu. Nesis/Aetos version is on the left and the Amigo version is on the right. This pattern repeats throughout this section.

Figure 5: Main autopilot settings menu.

The menu items follow the logic from the workflow:
Servo config is used to configure servo motors. Section 4.2.1 reveals the details.
Ground test is used to make sure that servos are correctly moving the controls. See section 4.2.2.
Limits is used to define valid operation envelope of the autopilot, section 4.2.3.
Parameters is used to define various controller parameters, section 4.2.4.
Tuning is an in-flight operation used to setup PID terms of the controller loops for the elevator and aileron. See section 5.5.

4.2.1 Servo Configuration
When setting up an autopilot, configuring the servos is the first step. Two servos are required: one for elevator and the other for ailerons. A servo can perform either role. Each servo has its own serial number. During the mechanical installation, write down the serial number of the servo which was connected to aileron and the serial number of the servo used for elevator.

Autopilot Installation Manual

4.2 Autopilot Settings

Select the servo to configure. A selection example is shown on Figure 6.

Figure 6: An example of servo selection based on serial number. Once serial number is selected a window with servo details opens, Figure 7.

Figure 7: An example of servo settings window.

The servo configuration window defines following parameters:

Function must match the servo mechanical connection. If servo with given serial number is connected to the aileron, then the function must also be Aileron. Change the function if necessary. You can choose between Aileron or Elevator.
Reversed has values No or Yes. Choosing correct value is a guessing game. Start with No and if ground test, described in section 4.2.2 fails, change it to Yes and vice versa.
Power defines how much power (=torque) shall be used by servo when moving its arm. 100% means total servo capacity. Try to avoid using more than 90% due to possible servo overheating. This also depends where and

Autopilot Installation Manual

4.2 Autopilot Settings

how servo is installed. In long term, try to find the lowest value, which still provides enough torque.
Holding power defines how much power is used when motor is not moving. This value depends on the power value above. If it is set to 50% this means that motor will use 50% of the torque set with the power parameter. For example, if power is set to 70% and holding power is set to 50%, the motor will use 35% of maximal power (torque) at standstill.
Backlash defines the amount of command system free travel, which is a combination of free play and elastic command resistance. It is given in degrees of servo arm movement. In ideal circumstances this shall be zero, but this is seldom the case.
Max speed is the maximal speed of servo arm movement in degrees per second. This value is usually set between 10 and 30 deg/s.
PPR tells how many pulses are needed for one rotation of internal stepper motor (always 200 for current servos). This is servo motor characteristics and shall not be changed.
Reduction is the gearbox reduction factor between the arm and stepper motor. (This factor is 4.57 for recent servos. But factors between 4 and 5 are also in use.) This is servo motor characteristics and shall not be changed.

In general, PPR, Reduction and Max speed shall not be changed and original values shall be kept. Change them only if Kanardia support team approves the changes.

4.2.2 Ground Test

The ground test is used to check correct servo motor movement. Figure 8 illustrates available options.

Autopilot Installation Manual

4.2 Autopilot Settings

Figure 8: Ground test movement options.

Forward shall move the command stick slightly forward (nose down). Make sure that command stick is not fully forward before this command is issued.
Backward shall move the command stick slightly backward.
Left shall move command stick slightly to the left.
Right shall move command stick slightly to the right.
You can issue the same command several times in the row. In many cases the weight of elevator control pulls stick forward on the ground. Servo is probably not strong enough to overcome this weight. In this case, hold the stick gently in the neutral position and execute the Forward/Backward commands. You will feel servo movement in your hand. If a movement appears in wrong direction, go back to the Servo Config and toggle the Reversed option. If servo moves a wrong command, go back to the Servo Config and modifiy the Function. Check both servos. Do not start tuning until you are 100% sure that ground test works correctly.

4.2.3 Operation Limits

Autopilot is allowed to operate only when the airplane is within operating limits of approved autopilot use.
The limits shall be defined by the airplane producer. These autopilot limits are much, much stricter than airplane capabilities. The limits are set around stable, coordinated flight at the economy cruise speed.
As soon as any parameter goes out of the limits, autopilot will be disconnected.

Autopilot Installation Manual

4.2 Autopilot Settings

Figure 9: An example of autopilot operation limits.

The following limits must be set:

IAS low . . . set this slightly below the economy cruising speed. This shall be significantly more that the stall speed. In fact, this should be set above VFE.
IAS high . . . set this slightly above the economy cruising speed. This shall be significantly less than VNE.
Max VS . . . set maximal allowed rate of climb or descent.
Max roll . . . maximal allowed roll for autopilot operation. Set this to 35 or less.
Max pitch . . . maximal allowed pitch for autopilot operation. Set this to 12 or less.

All limits must be checked with a flight test after the tuning has been completed. The limits must be set conservatively. Make any adjustments with great care.
Flying with the autopilot at a slow speeds is not allowed. It would be extremely dangerous. The dynamic characteristics of the airplane at low speed can be completely different from the characteristics at cruising speed.
Flying with the autopilot at high speeds is not allowed. It would be extremely dangerous. The dynamic characteristics of the airplane at high speed can be completely different from the characteristics at cruising speed.

Autopilot Installation Manual

4.2 Autopilot Settings

4.2.4 Controller Parameters
This window defines various parameters that are required for optimal operation. Some of these values can be only determined during flight test. Figure 10 illustrates an example.

Figure 10: An example of autopilot parameters.

Max arm mv defines maximal servo arm movement and is used to detect servo slip condition. When autopilot is engaged, servo remembers its arm position and treats this as a zero angle. During operation servo monitors virtual relative angle regarding the zero angle. If this virtual relative angle exceeds the Max arm mv value, the system reports a Motor slip error. Namely, servo does not measure angle directly, but it is counting steps from zero position. If motor is slipping (servo torque is too small) these counts will accumulate to a number (virtual angle) large enough to trigger the error. Due to slips, the arm did not move that much in reality.

Pitch target this is the maximal pitch angle that controller will require for a climb or a descent. This angle shall be smaller than max pitch from the limits, section 4.2.3.

Roll target is the maximal roll that can autopilot require in order to change direction. This angle shall be smaller than max roll from the limits, section 4.2.3.

Autopilot Installation Manual

4.2 Autopilot Settings

VS target is the target vertical speed, when change in the elevation is required. This speed shall be smaller than max vertical speed from the limits, section 4.2.3.
Max pitch rate tells how quickly pitch reference can change. Controller loops are calculated several times per second and they change their desired pitch all the time. If the outer loop vertical speed control loop asks for a quick change in pitch, the controller will limit the speed of change to the value entered here. The airplane will therefore make a smooth transition.
Max roll rate tells how quickly roll reference can change. Same as above, but now for the roll angle. If the outer loop heading control loop asks for a quick change in roll, the controller will limit the speed of change to the value entered here. The airplane will therefore make a smooth transition.
Max VS rate is the rate of change of the target vertical speed (it has dimension of acceleration). Similar as above, but now for vertical speed.
Turn comp defines amount of elevator compensation that is required when airplane is executing a turn. Pitch will be slightly increased during the turn. The increase grows with the roll angle.
Roll rate gain Value 0.9 is special and it means that Roll rate gain mode is disabled.

4.2.5 Tuning

Tuning is a in-flight operation. This operation is quite complex and is based on trial and error. Here only window description is given. Please refer to the section 5.5 for details about the tuning procedure.

When the Tuning option is selected from the Autopilot menu, a window illustrated on Figure 11 appears. Select one of four autopilot control loops to tune.

Autopilot Installation Manual

4.2 Autopilot Settings

Figure 11: Selection of an autopilot control loop.
Once loop was selected, a tune window appears. This window allows changing the PID controller parameters and observing the response at the same time. Figure 12 illustrates the example.

Figure 12: An example of roll loop tuning window.

The Ref. represents the loop target value. The target value is changed and airplane response is observed in the chart. The target is drawn in magenta color and the response is in yellow.
P, I and D terms are controller terms. The controller tries to reduce an error between a target (magenta) value and an actual value (yellow). Error is a difference between target and actual value.

P term defines controller's proportional (gain) part.

I term defines controller's integral (cumulative) part.

D term defines controller's derivative (rate of change) part.

Autopilot Installation Manual

5. Tuning

5 Tuning
Each autopilot must be taught how to fly a plane. This is done during tuning procedure. The following section provides you with a necessary knowledge how to properly tune the aircraft autopilot. The tuning of the autopilot is based on trial and error method. The operator has to gain knowledge and experience. It will take time and it is possible that more than one flight is needed to complete this task properly.

5.1 Controller
The controller is a system which monitors the process and calculate the required output of the actuator to keep the process variable within a set range. Autopilot actuators are motors which moves aircraft control surfaces and process is aircraft which is monitored with multiple different sensors.

5.1.1 PID controller
The Kanardia autopilot is using standard PID controllers. A PID controller is control loop mechanism employing feedback of controlling parameter. A PID controller continuously calculates an error value as the difference between a desired reference and a measured process variable (roll, pitch, VS and heading). It applies a correction based on proportional, integral, and derivative terms (denoted P, I, and D respectively). During tuning the operator is searching for optimal terms inside each loop: roll, pitch, vertical speed and heading.

P term a.k.a gain defines controller's proportional part. For example, if error is large and positive, the controller output will be also proportionately large and positive.
Unfortunately the P term is bad in removing small errors and here I-term comes into play.
I term is the integration time of the controller. It tells how fast the controller is trying to eliminate the steady-state error. The more error persists, the larger will be its time integral and consequently, the larger will be integral contribution.
D term is an estimate of the future trend of the error. It is based on the rate of error change. The more rapid the error change, the greater the controlling or dampening effect.

Autopilot Installation Manual

5.2 Step Change and Response

Typical block representation of the controller with feedback is shown on figure 13. The input to PID controller is the difference between reference and measured process value. Output of the controller must control the process to reduce the difference. Controller performance depends heavily on the accuracy of the sensed process variable and the precision of the actuator.

Reference

+ -

PID controller

Aircraft (Process)

Process variable

Figure 13: Typical PID controller block diagram.

If you are interested in PID controller, a good start may be the Wikipedia article, https://en.wikipedia.org/wiki/PID_controller.

5.2 Step Change and Response
Controller tuning is an iterative process. The operator triggers a step change of the reference value for each loop observing the aircraft response. Based on the aircraft response the terms of the controller are modified to get optimal ones. Analysis of response needs few technical terms which are explained with a figure 14:

2 1

5 3

Variable

Time 4
Figure 14: Step response of closed loop system.

1. Reference step change. 27

Autopilot Installation Manual

5.3 Cascade Controller

2. Overshoot. 3. Steady-state error - remaining error. 4. Response time - 90% of reference step. 5. Oscillations.

5.3 Cascade Controller
The main problem of the aircraft control is the fact that the aircraft is a complex process. We have to control at least elevator and ailerons. For each one we are using a cascade control system.
A cascade control involves the use of two controllers. The output of the first controller provides the reference for the second controller.
The example of cascade PID controller for an elevator is shown on figure 15. Note that there are two feedback loops and two controllers. Inner controller is controlling pitch of the aircraft and outer is controlling its vertical speed.

Reference

Vertical Speed

+ -

PID

+ -

PID

Elevator Aircraft

Vertical Speed

Pitch

Figure 15: Elevator cascade PID controller block diagram.

The important fact of this system is that outer loop response depends on the performance of the inner control loop. This means that inner control must be tuned first and the response of the inside loop must be good enough.

5.4 Controller Problems

The PID controller is very robust but sometimes the tuning does not provide any usable results. There are two major problems which influence the control loop behavior: mechanical backlash and motor slip.

Autopilot Installation Manual

5.5 Tuning Procedure

5.4.1 Backlash
is lost motion between the servo motor and the control surface. It has a negative impact on control loop performance. Mainly it results in constant and stable oscillation of aircraft around a problematic axis.
In this case it is best if the backlash in commands is removed. This needs some study where and why the backlash is present. However sometimes this is not doable without serious redesigning the autopilot mechanical linkage. Also it is possible that there is elastic backlash present.
In those cases we provided software backlash compensation. This means that on each servo motor reversal of the direction the motor moves for pre-specified angle. This angle is specified in the servo config dialogue specified in section 4.2.1.

5.4.2 Slip
When the momentum on the motor arm is too large the motor will slip. Slipping motor is unable to control the aircraft. Resolve slip issues on either axis before proceeding, either by increasing motor torque, changing hole on control arm or switching to a larger servo. If the motor is slipping there are no software options.
You can notice the slipping as a sudden small jump of the stick. The most common behavior of the aircraft with one of the servos slipping is that aircraft suddenly starts a turn and is unable to correct it.

5.5 Tuning Procedure
The tuning of the autopilot requires a ground preparation and a flight testing.

5.5.1 On-Ground

Before first flight the operator shall enter appropriate initial values for the autopilot, as described in section 7. The P-term of control loops shall be slightly smaller than P-term for similar aircraft. I-term shall be set to 30.0s and D-term to 0.0. Also the motor test shall be done.
AD-AHRS unit inside Horis, Emsis, Aetos or Nesis used for autopilot control must be leveled. When in level flight at desired cruising speed it shall show zero bank and pitch angles.

Autopilot Installation Manual

5.6 Tuning Rules

5.5.2 In-Flight
The flight test should be conducted on a calm, VFR day. Before commencing the in-flight tuning, ensure that you are at the safe altitude, you have enough fuel, clear weather, no traffic, no obstructions in the flight path, good visibility, no airspace conflicts, etc. It is highly recommended that you bring someone along on the autopilot test flight. At many points the pilot's attention will be divided between documentation, tuning autopilot, and maintaining situational awareness. An extra pair of eyes looking out is very helpful.
5.6 Tuning Rules
The operator should follow following rules during in-flight tuning and testing the autopilot:
Make notes during flight. Change only one parameter or term at once. Make small changes of parameters ot terms. Test every parameter change multiple times. Always tune P-term first, next I-term , last D-term . Keep D-term small - max. 1/10th of a I-term . I-term of inner loop shall be smaller than I-term of outer loop.

Autopilot Installation Manual

6. In-Flight Tuning

6 In-Flight Tuning
Kanardia autopilot system uses two-axis control: elevator and aileron. The tuning of autopilot is divided into two independent tasks. The operator shall tune the elevator control first and then move to aileron control tuning. Please note that during the tuning of the elevator the pilot is responsible to maintain roll angle of the aircraft and take care for direction as well. When tuning ailerons the autopilot will already keep control over elevator. Therefore it is a bit more difficult to tune the elevator.

6.1 Elevator

Cruise speed, altitude, trimmed
Pitch Tune

Elevator control consist of two cascaded control loops: pitch and vertical speed. The operator shall tune the pitch loop first. Without properly operating pitch loop the VS loop is impossible to tune.

During in-flight tuning the elevator will

Is response

OK?

be controlled by the autopilot servo. The pilot shall maintain aircraft leveled

yes

with ailerons during the elevator tuning

VS Tune

but it shall not move the elevator con-

trol.

Is response

OK?

More than 10 tries? yes

When tuning the VS loop there is a chance that operator can not get any

yes

meaningful response. If this happens

DONE

operator shall disengage autopilot and

re-trim aircraft and then proceed with

Figure 16: Elevator tune.

a tuning. The usual cause of VS loop malfunction is the bad pitch loop per-

formance. The operator should re-tune the pitch loop before proceeding. It is

also possible that one of fundamental controller problems is present. Please

see section 5.4 and resolve the issues first.

Autopilot Installation Manual

6.1 Elevator

6.1.1 Pitch tuning
When reaching target altitude and cruising speed make sure the aircraft is trimmed properly for a level flight. The operator shall enter the Tune dialog for pitch loop as shown in figure 12. By default the autopilot servo motor is in disengaged state. The autopilot engages every time the operator selects new Reference value and disengages every time the operator changes any of the P-, I- or D- term.
We provided a real tuning procedure example on figure 17. We choose 0.45 for initial P-term . Then we gradually increased the P-term by 0.2 until we reach satisfactory response. There should be small overshoot present and the servo motor should quickly react to the pitch reference change. Before every step change set reference to 0 and wait for the aircraft to stabilize. Follow provided flow charts for tuning each controller term.

P-term shall be tuned following flow chart shown in figure 6.1.1. Start with low P-term and then gradually increasing it, until you reach satisfactory response.
Cruise speed, altitude, trimmed

1. Set 0 degrees reference angle.
2. Steady state - Wait enough time for controller to stabilize. Around 10 seconds usually is enough.
3. Step change - Change reference angle by 3-5 degrees. This depends on aircraft. In our example we choose 4 degrees.
4. Observe - Wait 10-15 seconds.
5. P-term - Depending on the aircraft response we have to modify the P-term . Please see example tuning on figure 17 for example responses and appropriate actions.
6. Repeat - Go back to step 1.

Set Reference to 0°

Wait 10 seconds

P=P/2

Is pitch

yes

oscillating?

Step change Reference = +3-5°

P=P+0.2

Wait 10 seconds

Is response

OK?

yes

Tune I-term

Autopilot Installation Manual

6.1 Elevator

I-term shall be set to start value. Tune it following flow chart shown in figure 6.1.1. Start with high I-term and then gradually decrease it, until you reach satisfactory response.

I-term will add some oscillations, do not worry about this for now. The D-term should damp it enough. If you get too much overshoot or too much oscillations it is possible that you have basic control loop problems as described in 5.4.

1. Set 0 degrees reference angle.
2. Steady state - Wait enough time for controller to stabilize. Around 10 seconds usually is enough.
3. Step change - Change reference angle by 3-5 degrees. This depends on aircraft. In our example we choose 4 degrees.
4. Observe the response - Wait approx. 1015 seconds.
5. Modify the I-term according on the aircraft response. Please see example tuning on figure 17 for example responses and appropriate actions. If you would like to decrease the response time I-term should be decreased.
6. Repeat - Go back to step 1.

I = 10.0 s

Set Reference to 0°

Wait 10 seconds Step change
Reference = +3-5°

I = I 2.0 s

Wait 10 seconds

Is response

OK?

yes

Tune I-term

D-term start value shall be set to 0.1s. Then it should be gradually increased, until you reach satisfactory response. The maximum D-term should not exceed 1/5th of a controller I-term . To tune D-term of the pitch control loop follow flow chart shown in figure 6.1.1.

Autopilot Installation Manual

6.1 Elevator

1. Set 0 degrees reference angle.
2. Steady state - Wait enough time for controller to stabilize. Around 10 seconds usually is enough.
3. Step change - Change reference angle by 3-5 degrees. This depends on aircraft. In our example we choose 4 degrees.
4. Observe - Wait approx. 10-15 seconds.
5. D-term - Depending on the aircraft response we have to modify the D-term . Please see example tuning on figure 17 for example responses and appropriate actions. If you would like to increase damping you should increase the value of D-term .
6. Repeat - Go back to step 1.

D = 0.0 s

Set Reference to 0°

Wait 10 seconds

Step change Reference = +3-5°

D = D + 0.2 s

Wait 10 seconds

Is response

OK?

yes

DONE

Testing After successful tuning of pitch loop the operator shall test the pitch loop with different reference angles. The aircraft response shall be with small overshoot and without oscillations.
Be aware that setting excessive reference pitch angle values will cause that aircraft will pitch up or down quickly. Depending on the aerodynamics of the aircraft the airspeed can change quickly. Keep the aircraft within safe limits.

Autopilot Installation Manual

6.1 Elevator

(a) P too low.

(b) P still too low.

(d) Start I for pitch is 8s.

(e) Lower I - better.

(f) Lower I - even better.

(g) Add D=I/20.

(h) D-term too big ... D=D/2.

(i) Decrease I slightly - DONE.

(j) Test also in minus

Figure 17: Example of pitch tuning process.

Autopilot Installation Manual

6.1 Elevator

6.1.2 Vertical speed tune
After successful tuning the pitch control loop the operator should proceed with tuning the vertical speed loop. The basic operation is similar to the one we described in pitch tuning section. The operator should set the initial controller parameters and the aircraft shall be trimmed and in level flight. If the aileron axis is not tuned the pilot must maintain the aircraft leveled in roll axis.
The operator shall tune the P-term first then move to I-term and tune D-term as a last parameter. Example tuning process of vertical speed loop is given in figure 18.

P-term We start by tuning the P-term . Set the I-term to maximum value and D-term to 0. Please remember that is best if you start with low P-term and then gradually increasing it, until you reach wanted response. A good start value for VS loop is 0.01.
By tuning the P-term the operator must achieve pretty confident response of the aircraft to the step change of the reference vertical speed. Do not worry if the aircraft pitches down after initial pitch up reaction. This is normal and it is related to the loss of airspeed. The tuning of I-term should handle this situation.
If the aircraft starts to oscillate with large amplitude around pitch axis the P-term is too high. You will have to decrease it to the half of the current value.

Problems In case that it is impossible to tune the autopilot there is a great chance that you are experiencing one of the basic controller problems described in 5.4.
However in the VS loop there is another problem that could be present. The vertical speed control loop is using measured vertical speed as a feedback value. The vertical speed in Kanardia instruments is measured as a derivative of a static pressure. If the aircraft is using cabin static pressure connection or the pito-static tube located under the wing, static pressure will change rapidly with the change of the aircraft angle of attack. With bad static pressure connection autopilot will be unable to control vertical speed correctly.

I-term With properly tuned P-term of VS loop we should enable I-term . Set it to initial value of 15s and test the response. Decrease the I-term

Autopilot Installation Manual

6.1 Elevator

gradually until you achieve proper response. Proper response of the aircraft has a small overshoot and small steady-state error. Make sure that I-term of VS loop is at least twice the I-term of pitch loop.
D-term After I-term set small D-term for the VS loop. Start with small value. The starting D-term should be around I-term /20. Increase it only if you do not observe any oscillations. The maximum D-term should not exceed I-term /5.
Testing After tuning the operator should test the PID -terms with different vertical speeds, both in climb and in descend. Please note the autopilot will not automatically adjust the airspeed. If the airspeed is too high or too low the autopilot will disengage. Make sure that during the tests the aircraft stays within operational limits.

Autopilot Installation Manual

6.1 Elevator

(a) P way too low.

(b) P still too low.

(d) P is now just enough.

(e) Start value for I.

(f) Lower I - even better.

(g) I should be ok.

(h) D = I/20.

(i) Increase D slightly - DONE.

(j) Test also in minus

Figure 18: Example of vertical speed tuning process.

Autopilot Installation Manual

6.2 Aileron tune

6.2 Aileron tune
With properly operating elevator autopilot it is much easier to tune the remaining aileron axis. For aileron axis we have to tune two control loops: roll and heading.

6.2.1 Roll tune
There are two major operating modes for roll loop. The operator can select between modes by setting the roll rate gain parameter. If it is set to "Disabled" the roll loop is controlling the roll angle directly with the PID controller. If the roll rate gain parameter is set to any other value the roll controller will operate in roll-rate mode.
The older tuning method with disabled roll rate gain is not recommended for new installations. In this manual we will describe only the tuning with the roll rate controller.

Roll rate gain tells controller the factor to calculate the desired roll rate from the roll angle error. If this parameter is set to 1.0 this means that autopilot will try to correct the error of 5 with an roll rate of 5/s. For start it should be set to 1.0. This value is fine for most installations.

P-term With Roll rate gain parameter set to 1.0 we are now tuning the roll rate and not the roll angle. For this you will notice dashed lines in tuning dialog which marks the selected Maximum Roll Rate parameter. Before first tuning we should set this parameter to the default safe value of 5/s.
We start tuning with a low value for P-term . On our example on Figure 19 we started with P-term of 0.5. Note that I-term is set to a bit lower starting value of 10.0s. The P-term is then gradually increased to obtain fast enough response without oscillations.

I-term When tuning the I-term the starting value should be around 10-12s. After setting the P-term we can try to decrease I-term to improve response, but we should never get to a response with oscillations. If this happens the I-term shall be increased by at least 2.0s.

D-term shall be always set to 0 in roll-rate-gain mode.

Autopilot Installation Manual

6.2 Aileron tune

(a) P way too low.

(b) P still too low.

(d) P is now just enough.

(e) Start value for I.

(f) Lower I - oscilations - go-back.

(g) Test into other direction. Figure 19: Example of roll rate tuning process.

6.2.2 Heading tune

If the roll control loop is operating properly the tuning of the heading loop is usually simple. However the operator must check that response of the aircraft is good enough under operating all conditions. The starting values for P-term shall be 1.0 and I-term 25.0s. The step angle for testing the

Autopilot Installation Manual

6.3 Fine tuning

controller response should be 10 larger than selected Target Roll Angle.

P-term should be set to 1.0 as a starting point. After step change it should be increased if the response of the aircraft heading is too slow. The usual P-term values range from 1.0 to 1.8.

I-term is used to improve the time needed to eliminate steady-state error. The I-term should be set in between 15.0s and 25.0s. Decreasing the I-term will decrease the time needed to establish new heading. At the same time it is possible that low enough I-term will cause the overshoot of the reference heading. This is usually undesired behaviour. In this case we should increase the I-term .
Test for overshoot shall be done also for small changes of reference heading. Try to test with small step change of 5. If there is too much overshoot increase the I-term .

D-term shall remain set 0.0

6.3 Fine tuning
There are some parameters that should be adjusted after the basic tuning is done. This parameters will improve autopilot performance.

6.3.1 Roll feed forward

This parameter sets how much the elevator control is pulled or pushed during the turn. When initiating the turn observe the pitch of the aircraft. If it dives when initiating turn and climbs when finishing it you have to increase Roll feed forward parameter. For most ultra-light aircraft's it should be around 0.2 and 0.3.
For start it should be set to 0.1. Now with autopilot in level mode change autopilot heading. If the aircraft still dives when initiating turn you should increase the this parameter by 0.1 and re test. Repeat this two steps until you find a value which is applicable for your aircraft.

Autopilot Installation Manual

7. Quick Configuration

(a) P way too low.

(b) P still too low.

(d) P is now just enough.

(e) Start value for I.

(f) Test small angle.

Figure 20: Example of heading tuning process.

6.3.2 Motor power
If the stick is very hard to overcome the torque of the motor the torque of the appropriate axis should be lowered. This will reduce the current consumption of the motor and it will reduce the motor heating. Also the pilot will be able to override the autopilot with more appropriate force.

7 Quick Configuration

This is a quick reminder of Nesis/Aetos commands inputs required to configure the autopilot system for a know airplane.

Autopilot Installation Manual

7.1 Configure Servos

7.1 Configure Servos
Define which servo is used for elevator and which for aileron. Write down their serial numbers. Now configure the motor as elevator or as aileron. Other values are:
Reversed - select Yes or No depending on the results of the Direction Test.
Power: 80% Holding power: 80% Backlash: 0 Max speed: 30 PPR : 200 Ratio: 4.5

7.2 Direction Test
Options Service Mode Autopilot Test.

Press move forward, backward, left, right. The yoke/stick should move in the correct direction. If the movement is opposite, change the Reversed parameter in Servo Configuration.

7.3 Operating Limits
Options Service Mode Autopilot Limits.
Minimum IAS: 140 km/h Maximum IAS: 200 km/h Maximum vario: 6 m/s Maximum Roll: 30 Maximum Pitch: 12
Values shown above are given for example only use appropriate limits for your airplane. If the aircraft exceeds this limits the autopilot will disengage immediately and the reason will be shown on the display.

Autopilot Installation Manual

7.4 Tuning

7.4 Tuning
Enter values from tables given in section B. Options Service Mode Autopilot Tune and then:
Pitch Manual tune, Vario Manual Tune, Roll Manual Tune, Heading Manual Tune Please fill the report from appendinx A once the installation and tuning is complete and send the form to Kanardia. The form is needed for future references and maintenance purposes.
8 Safety Measures

Autopilot system is not terrain or traffic aware and it will not make any avoidance action or issue any terrain warning!

The autopilot is directly linked with aircraft commands thus it presents high risk if something fails or goes wrong. Kanardia autopilot is using following safety measures in order to reduce this risk to a minimum.
Automatic disable when aircraft is outside safe operating limits.
Multiple Manual disable options.
Servo power switch immediately cuts the power of servo motors.
Motor override the servo motor can be safely overridden, but the commands are jerky.
Safety pin will break if the motor or gears inside are mechanically blocked.
Mechanical limiter limits the movement of the motor lever preventing mechanical lock-up.
The servomotors are designed to be over-driven with external force from command stick with no damage.

Autopilot Installation Manual

8.1 Automatic Disable

8.1 Automatic Disable
The Autopilot will disengage automatically and immediately when any of the following values is out of the range:
minimum autopilot IAS, maximum autopilot IAS, maximum autopilot vertical speed, maximum autopilot roll angle, maximum autopilot pitch angle.
These values must be configured correctly and they depend on the type and performance of the aircraft. See section 4.2.3 for limit details.

8.2 Manual Disable
The following ways may be used to disable autopilot system manually:

1. Select the Disable option from the autopilot menu of Nesis/Aetos.

2. On Nesis/Aetos, press the User button when the autopilot menu is active (double click on user button).

3. On Nesis/Aetos, make a long press on the User button the long press function must be properly configured.

4. When an external push button is installed on a command stick, press the button to disable the autopilot. Nesis/Aetos or Amigo must be properly configured.

5. When Joyu is connected to the CAN bus and its buttons are properly configured, press (or long press) the corresponding button on Joyu.

6. When Amigo is connected to the CAN bus, press the top knob to disconnect aileron servo and bottom knob to disconnect the elevator servo.

7. On Nesis only, make a long touch on autopilot status window.

Autopilot Installation Manual

8.3 Electrical Disable

8.3 Electrical Disable
The autopilot motors are disconnected as soon as power supply is removed. Therefore it is essential that the power to the servo motors can be cut with removable fuse or with a separate switch. See section 3.1 for more details.
8.4 Mechanical Disable
The servo motor torque is small enough that it can be overridden by higher force in the command stick even when servo is operating with 100% torque. However, the commands feel jerky and precise steering is a bit challenging. Safety pin is the inserted between the servo arm and the servo motor shaft. In the very unlikely case of blocked motor or blocked gears, pilot can use force on the command stick, which will break the pin and release servo motor shaft from the command system.

Autopilot Installation Manual A. Autopilot Installation And Tuning Form

A Autopilot Installation And Tuning Form

Date Customer Performed by

Airplane/Type Registration Signature

Setting Model Lever Lever hole PPR Reduction

Elevator

Servo motor settings

Aileron

Setting Reversed Power Hold pwr Backlash Top speed

Elevator

Aileron

Max IAS Min IAS Max VS

Operating limits
Max roll Max pitch -

Configuration parameters

Max arm mv Pitch target
Roll target VS target
-

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

Parameter P-term I-term D-term

Pitch

Tuning parameters

Vario

Roll

Heading

Autopilot Installation Manual

B. Parameters For Known Airplanes

B Parameters For Known Airplanes
Tables in this section list the tuning parameters for autopilots we have installed in different airplanes. If your installation is identical, then these values should give you a very reasonable autopilot behavior. However, when the hardware installation is a bit different (usually, it is) or if different servo arm was used or a different hole in the servo arm, etc, then these values may not be completely suitable and re-tuning is necessary. Some loops given below are using special values. RFF means Roll Feed Forward, VS is Vertical Speed, RRG means Roll Rate Gain.

B.1 Ekolot Topaz

Table 1: Topaz configuration parameters

Max arm mv Pitch target
Roll target VS target
-

40 12 20 3m/s -

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

10/s 3/s 1.5m/s2
0.0
0.9??

Table 2: Topaz PID values

Parameter Pitch

Roll

P-term

1.0

0.018

0.8

I-term

14.0

19.0

D-term

0.16

0.02

Heading 0.75 28 0.3

B.2 Pipistrel Sinus

Autopilot Installation Manual

B.3 Aeropilot Legend 540

Table 3: Sinus configuration parameters

Max arm mv Pitch target
Roll target VS target
-

40 12 20 3m/s -

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

5/s 3/s 1.5m/s2
0.0
disabled

Parameter P-term I-term D-term

Table 4: Sinus PID values

Pitch

Roll

0.5

0.02

0.5

7.0

12.0

8.0

0.16

0.2

0.02

Heading 1.0 25 0.2

B.3 Aeropilot Legend 540

Table 5: Legend 540 configuration parameters

Max arm mv Pitch target
Roll target VS target
-

40 10 20 3m/s -

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

5/s 3/s 1.0m/s2
0.2
disabled

Table 6: Legend 540 PID values

Parameter P-term I-term D-term

Pitch 0.65 4.0 0.2

VS 0.017 15.0 0.32

Roll Heading

0.9

0.6

0.16

0.2

B.4 Evector Eurostar EV97
49

Autopilot Installation Manual

B.5 Aerospool Dynamic WT9

Table 7: EV97 configuration parameters

Max arm mv Pitch target
Roll target VS target
-

40 12 20 3m/s -

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

3/s 5/s 1.5m/s2
0.3
disabled

Parameter P-term I-term D-term

Table 8: EV97 PID values

Pitch

Roll

0.4

0.025

0.7

7.0

12.0

0.0

0.2

Heading 0.9 26 0.2

B.5 Aerospool Dynamic WT9

Table 9: WT9 configuration parameters

Max arm mv Pitch target
Roll target VS target
-

30 10 20 2.5m/s -

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

3/s 3/s 1.0m/s2
0.2
2.0

Table 10: WT9 PID values

Parameter Pitch

Roll

P-term

1.2

0.024

0.6

I-term

6.5

15.0

4.5

D-term

0.5

0.3

0.4

Heading 1.5 26 0.14

B.6 Roko Aviation
50

Autopilot Installation Manual

B.7 Aeroprakt

Table 11: NG6 configuration parameters

Max arm mv Pitch target
Roll target VS target
-

30 10 20 2.5m/s -

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

3/s 3/s 1.0m/s2
0.2
disabled

Parameter P-term I-term D-term

Table 12: NG6 PID values

Pitch

Roll

1.2

0.017

0.6

6.5

15.0

4.5

0.52

0.32

0.4

Heading 0.6 26 0.2

B.7 Aeroprakt

Table 13: A22 & A32 configuration parameters

Max arm mv Pitch target
Roll target VS target
-

30 10 20 2.5m/s -

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

4/s 5/s 1.0m/s2
0.2
2.0

Table 14: A22 & A32 PID values

Parameter P-term I-term D-term

Pitch 1.9 5.0 0.2

VS 0.020 20.0 0.2

Roll Heading

0.45

5.0

0.16

0.3

B.8 Direct Fly
51

Autopilot Installation Manual

B.9 Comco Ikarus

Table 15: TG configuration parameters

Max arm mv Pitch target
Roll target VS target
-

30 10 15 2.5m/s -

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

2/s 3/s 1.0m/s2
0.2
2.0

Parameter P-term I-term D-term

Table 16: TG PID values

Pitch

Roll

0.8

0.014

0.6

6.5

12.0

4.5

0.44

0.10

0.04

Heading 0.6 26.0 0.10

B.9 Comco Ikarus

Table 17: C-42C configuration parameters

Max arm mv Pitch target
Roll target VS target
-

30 10 15 2.5m/s -

Max pitch rate Max roll rate Max VS rate Turn comp Roll rate gain

3/s 3/s 1.0m/s2
0.2
1.8

Table 18: C-42C PID values

Parameter Pitch

Roll

P-term

1.1

0.016

0.85

I-term

3.0

8.0

6.0

D-term

0.2

0.0

0.16

Heading 0.5 26.0 0.0

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