RX72T

2.2.1 User interfaces

The user interfaces of this system are given in Table 2-1.

The port interfaces of this system are given in Table 2-2.

2.2.2 Peripheral functions

The peripheral functions used in this system are given in Table 2-3.

(1) 12-bit A/D converter (S12ADH)
U phase current (Iu), W phase current (Iw), inverter bus voltage (Vdc) and rotation speed reference are measured by using the single scan mode (use hardware trigger). The sample-and-hold function is used for U phase current (Iu) and W phase current (Iw) measurement.

(2) Compare match timer (CMT)
The channel 0 of the compare match timer is used as a 500 [µs] interval timer.

(3) Multi-function timer pulse unit 3 (MTU3d)
The operation mode varies depending on channels. On channels 3 and 4, output (active level: high) with dead time is performed using the complementary PWM mode. The channel 1 of MTU3 operates in phase counting mode, where the counter is incremented or decremented according to the phase difference between Phase-A and Phase-B signals from the encoder.

(4) General PWM Timer (GPTW)
The operation mode varies depending on channels. On channels 4, 5, and 6, output (active level: high) with dead time is performed using the PWM Output Operating mode. The channel 3 operates in phase counting mode, where the counter is incremented or decremented according to the phase difference between Phase-A and Phase-B signals from the encoder. The channel 9 is used as a free-run timer for speed measurement.

(5) Port output enable 3 (POE3B)
PWM output ports are set to high impedance state when an overcurrent is detected (when a falling edge of the POE0# port is detected) and when an output short circuit is detected.

The setting of the PWM output timer is selected by the following macro definition.

2.3.1 Software file configuration

The folder and file configuration of the sample programs are given below.

Figure 2-2 Folder and file configuration: This diagram shows the hierarchical structure of the software project files for the motor control application. It is organized into layers: `application` (main, user_interface, ics, board), `middle` (interface, common, control, inverter, mcu, sensor), and `config`. Each folder contains specific `.h` and `.c` files or libraries, with brief descriptions of their functions (e.g., `main.c` for main function, `r_mtr_pi_control.c` for PI controller function definition).

Notes: 1. Regarding the specification of Analyzer function in the motor control development support tool 'Renesas Motor Workbench', please refer to Chapter 4. The identifier 'ics/ICS' (ICS is the previous motor control development support tool ‘In Circuit Scope') is attached to the names of folders, files, functions, and variables related to 'Renesas Motor Workbench'.

2.3.2 Module configuration

The module configuration of the sample programs is described below.

Figure 2-3 Module Configuration: This diagram visually represents the software module architecture. It shows three main layers: `Application Layer` (User Application), `Middle Layer` (Motor Control Process), and `Device Layer` (MCU Register Access, Inverter Driver, Sensor Driver), with the `H/W Layer` at the bottom. Data flow and function calls between modules like `main.c`, `r_mtr_driver_access.c`, `r_mtr_interrupt_carrier.c`, `r_mtr_foc_current.c`, `r_mtr_ctrl_encoder.c`, and `r_mtr_ctrl_rx72t.c` are depicted.

3.1.1 Motor Start/Stop

The start and stop of the motor are controlled by input from the Analyzer function of ‘Renesas Motor Workbench' or the SW1 switch of the RSSK board. A general-purpose port is assigned to SW1. The port is read within the main loop. When the port is at a 'Low' level, the software determines that the motor should be started. Conversely, when the level is switched to 'High', the program determines that the motor should be stopped.

3.1.2 A/D Converter

3.1.3 Position Profile Generation

(Position Profile of Trapezoidal Curve for Speed Command Value)

In vector control software for PMSM with encoder, position profile generation is used to create the command value (input position value). The implementation uses each control cycle to manage acceleration and maximum speed relative to the target position value.

Figure 3-1 Position Profile Generation: This graph illustrates the generation of a position command profile, typically a trapezoidal curve for speed. It shows how speed and position change over time. Key variables like com_s2_ref_position_deg (target position), com_f4_accel_time (acceleration time), and com_s2_max_speed_rpm (maximum speed) are used to define the profile.

Enter the following variables from the Analyzer to create a command value:

• Position reference [degree] (com_s2_ref_position_deg)
• Acceleration time (com_f4_accel_time)
• Maximum speed command value (com_f4_accel_max_ref_speed_rad)
• Position stabilization wait time (com_u2_ref_pos_interval_time)

3.1.4 Speed Measurement

To achieve better real-time performance and higher speed resolution at low speeds, this system uses the encoder signal edge interval to calculate speed. Speed extrapolation is used in PI control calculation. Considering the difference between rise and fall times and the accuracy of the encoder signal's quadrature, speed is calculated based on elapsed time and angle change over one period of the encoder's Phase-A or Phase-B signals.

3.1.5 Modulation

The target software of this application note uses pulse width modulation (PWM) to generate the input voltage to the motor. The PWM waveform is generated by the triangular wave comparison method.

Figure 3-4 Definition of Duty: This diagram defines the duty cycle of a PWM signal. It shows a single PWM pulse with ON time (TON) and OFF time (TOFF) within a period (TON + TOFF). The formula Duty = (TON / (TON + TOFF)) * 100 [%] is provided. It also shows how the average voltage relates to the duty cycle.

Modulation factor m is defined as follows:

m = V / E

where: m: Modulation factor, V: Voltage command value, E: Inverter bus voltage.

The voltage command can be generated by setting the PWM compare register properly to obtain the desired duty.

3.1.6 State Transition

Figure 3-5 State Transition Diagram of Vector Control PMSM with Encoder Software: This diagram illustrates the operational states of the motor control software. It shows transitions between SYSTEM MODE states (INACTIVE, ACTIVE, ERROR) triggered by EVENTs (user operation, error detection). It also shows RUN MODE states (INIT, BOOT, DRIVE) and how Control Config (Current, Speed, Position, Torque, Voltage) changes.

The software state is managed by ‘SYSTEM MODE' and ‘RUN MODE'. 'Control Config' shows the active control system.

• (1). SYSTEM MODE: Indicates the operating states of the system. Transitions occur based on events. It has three states: motor drive stop (INACTIVE), motor drive (ACTIVE), and abnormal condition (ERROR).
• (2). RUN MODE: Indicates the condition of the motor control. It transitions sequentially when 'SYSTEM MODE' is 'ACTIVE'.
• (3). EVENT: When an 'EVENT' occurs in each 'SYSTEM MODE', the 'SYSTEM MODE' changes as shown in the table below.

3.1.7 Startup Method

Figure 3-6 Startup Position Control of Vector Control PMSM with Encoder Software: This graph depicts the sequence of operations during the startup phase for position control. It shows how Id reference, Iq reference, speed reference, and position reference change over time as the system transitions through MTR_MODE_INIT, MTR_MODE_BOOT, and MTR_MODE_DRIVE.

Figure 3-7 Startup Speed Control of Vector Control PMSM with Encoder Software: Similar to Figure 3-6, this graph illustrates the startup sequence for speed control, showing how Id reference, Iq reference, and speed reference evolve during initialization, boot, and drive modes.

This section shows the software implementation of d-axis and encoder alignment methods. The d-axis alignment method is used as startup control for position control, in initialization mode (MTR_MODE_INIT) and Boot mode (MTR_MODE_BOOT). In drive mode (MTR_MODE_DRIVE), vector control is implemented for PMSM with Encoder. Each reference value setting of d-axis current, q-axis current, and speed is managed by respective status.

For details of the position control of a vector-controlled PMSM using an encoder, refer to the application note ‘Vector control of permanent magnet synchronous motor with encoder: algorithm'.

3.1.8 System Protection Function

This control program includes the following error statuses and executes emergency stop functions in case of respective errors. Table 3-4 shows the setting values for the system protection function.

• Over-current error: Detected by both hardware and software methods. An emergency stop signal from hardware (detection) sets PWM output ports to high impedance state. U, V, and W phase currents are monitored. The CPU executes an emergency stop (software detection) if an over-current is detected. The limit is calculated from the nominal motor current [MP_NOMINAL_CURRENT_RMS].
• Over-voltage error: Inverter bus voltage is monitored. The CPU performs an emergency stop upon detecting over-voltage, considering resistance errors in the detection circuit.
• Under-voltage error: Inverter bus voltage is monitored. The CPU performs an emergency stop upon detecting under-voltage, considering resistance errors in the detection circuit.
• Over-speed error: Rotation speed is monitored. The CPU performs an emergency stop if the speed exceeds the limit value.

3.4.1 Main Process

Figure 3-9 Main Process Flowchart: This flowchart outlines the main execution sequence of the control program. It includes initialization steps for peripherals, user interface, variables, sequence process, and Analyzer. It also shows the power supply stabilization wait, decision points for Analyzer vs. Board UI, parameter input, motor operation mode changes, LED control, and watchdog timer clearing.

3.4.2 Carrier Synchronous Interrupt Handling (Vector Control using Encoder)

Figure 3-10 50 [µs] Cycle Interrupt Handling: This flowchart details the steps executed within the 50-microsecond interrupt service routine. It covers encoder counter processing, current and voltage acquisition, error checks, offset adjustments, coordinate transformations (UVW to dq), current PI control, decoupling control, voltage limiting, phase-lead compensation, and PWM duty calculation.

3.4.3 500 [µs] Interrupt Handling

Figure 3-11 500 [µs] Interrupt Handling: This flowchart describes the actions taken during the 500-microsecond interrupt. It includes decisions based on SYSTEM MODE (INACTIVE, ACTIVE) and RUN MODE (INIT, BOOT, DRIVE), handling Hall and encoder signals, setting various references (position, speed, current), and managing state transitions.

3.4.4 Over Current Detection Interrupt Handling

Figure 3-12 Over Current Detection Interrupt Handling: This flowchart shows the process when an over-current condition is detected. It leads to a motor stop process and clearing of high-impedance status.

3.4.5 Encoder Count Capture Interrupt Handling

Figure 3-13 Encoder Count Capture Interrupt Handling: This flowchart illustrates the steps performed upon an encoder count capture interrupt. It includes checking if encoder alignment is finished, accumulating encoder counts, calculating position, detecting zero speed, and calculating speed.

3.4.6 Hall Signal Interrupt Handling

Figure 3-14 Hall Signal Interrupt Handling: This flowchart details the handling of Hall sensor signals. It shows detection of Hall signals, calculation of rotor angle, error handling, and disabling the Hall interrupt, depending on the RUN MODE.

4.1 Overview

‘Renesas Motor Workbench' is a support tool for motor control system development. It can be used with the target software of this application note to analyze control performance. The user interfaces provide functions like rotating/stop command and setting rotation speed reference. Refer to the ‘Renesas Motor Workbench User's Manual' for usage and more details. ‘Renesas Motor Workbench' can be downloaded from the Renesas Electronics Corporation website.

Figure 4-1 Renesas Motor Workbench – Appearance: This figure shows screenshots of the Renesas Motor Workbench software. It displays the "Main Window" with options for file management, connection, and configuration, and the "Analyzer Window" which includes controls for commander, scope, variables, and data acquisition.

Set up for ‘Renesas Motor Workbench’

1. Start 'Renesas Motor Workbench' by clicking its icon.
2. Click on [File] and select [Open RMT File(O)] from the drop-down Menu. Select the RMT file from the following location of the e2studio/CS+ project folder: '[Project Folder]/application/user_interface/ics/'.
3. Use the 'Connection' [COM] select menu to choose the COM port.
4. Click on the 'Analyzer' icon in the Select Tool panel to open the Analyzer function window.
5. Refer to '4.3 Operation Example for Analyzer' for motor driving operation.

4.2 List of Variables for Scope Function 'Analyzer'

Table 4-1 is a list of variables for the Analyzer. These variable values are reflected to the protect variables when the same values as g_u1_enable_write are written to com_u1_enable_write. Variables with (*) do not depend on com_u1_enable_write.

4.3 Operation Example for Analyzer

This section provides an example of motor driving operation using the Analyzer's 'Control Window'. Refer to the 'Renesas Motor Workbench User's Manual' for specifications of the 'Control Window'.

- Driving the motor

1. Confirm the check-boxes in the [W?] column for 'com_u1_mode_system', 'com_s2_ref_speed_rpm', and 'com_u1_enable_write'.
2. Input a reference speed value in the [Write] box of 'com_s2_ref_speed_rpm'.
3. Click the 'Write' button.
4. Click the 'Read' button. Confirm the [Read] box values for 'com_s2_ref_speed_rpm' and 'g_u1_enable_write'.
5. Set the same value as 'g_u1_enable_write' in the [Write] box of 'com_u1_enable_write'.
6. Write '1' in the [Write] box of 'com_u1_mode_system'.
7. Click the 'Write' button.

Figure 4-2 Procedure - Driving the motor: This figure illustrates the steps for driving the motor using the Analyzer. It shows UI elements like the 'Read' and 'Write' buttons, check boxes, and input fields for variables.

- Stop the motor

1. Write '0' in the [Write] box of 'com_u1_mode_system'.
2. Click the 'Write' button.

Figure 4-3 Procedure - Stop the motor: This figure shows the steps to stop the motor by setting the 'com_u1_mode_system' variable to '0' and clicking 'Write'.

- Error cancel operation

1. Write '3' in the [Write] box of 'com_u1_mode_system'.
2. Click the 'Write' button.

Figure 4-4 Procedure - Error cancel operation: This figure illustrates how to cancel an error by setting the 'com_u1_mode_system' variable to '3' and clicking 'Write'.

4.4 Operation Example for User Button

This section provides examples of motor driving operations using the User Button.

- Driving or Stop the motor in position control mode
By setting as shown in Figure 4-5, driving and stopping change each time the button is pressed.

Figure 4-5 Driving or Stop the Motor in position control mode: This figure shows the User Button interface for controlling the motor in position control mode, illustrating how button presses toggle between start/stop states.

- Change position
By setting as shown in Figure 4-6, enter the command position and press the button to change the position.

Figure 4-6 Change position: This figure displays the User Button interface for changing the motor's position, showing how to input a 'Position Reference' value and trigger the update.

- Driving or Stop the motor in speed control mode
By setting as shown in Figure 4-7, driving and stopping change each time the button is pressed.

Figure 4-7 Driving or Stop the Motor in speed control mode: This figure shows the User Button interface for controlling the motor in speed control mode, illustrating how button presses toggle between start/stop states.

- Change speed
By setting as shown in Figure 4-8, enter the command speed and press the button to change the speed.

Figure 4-8 Change speed: This figure displays the User Button interface for changing the motor's speed, showing how to input a 'Speed Reference' value and trigger the update.