TARS-IMU Sensors for Traction Control and Stabilization

Background

In the past, off-road wheeled and track equipment has been primarily controlled by the operator of the equipment. This includes equipment for the agriculture, construction, oil and gas, and defense industries. However, with operator control of the equipment only, the drive wheels or tracks could begin to slip or spin before the operator becomes aware of the issue. This could result in damage to the equipment or landscape and potential operator injury. As a result, more time and cost can be incurred to complete a jobsite. Also, as experienced operators retire or leave the trades, newer and inexperienced operators can add additional time and cost as they ascend the learner curve on use of the equipment.

Solution

The Honeywell Transportation Attitude Reference System, or TARS-IMU, is a packaged sensor array designed to report vehicle angular rate, acceleration, and attitude data for demanding applications in industries such as heavy-duty, off-highway transportation.

TARS-IMU enables autonomous vehicle characteristics and enhances efficiency and productivity by reporting key data required to automate and monitor movements of vehicle systems and components. The sensor fusion algorithm can be customized for specific vehicle applications through on-board firmware, allowing movement data to be filtered for extraneous environment and vehicle movements.

The Honeywell TARS-IMU sensor array can be programmed to communicate with the operator and/or the control system for a predetermined set of values.

As more equipment becomes integrated with smart electronics, the equipment is able to operate more efficiently with inputs from the electronics and the operator. Reference the Honeywell TARS-IMU sensor as illustrated in the diagrams of Figures 1 and 2.

In the left diagram of Figure 2, the equipment is positioned as designed. In the center diagram, the wheels or tracks begin to slip and/or spin with reference the front set. When the TARS sensor senses a movement that does not match the expected movement, the equipment through engine response, transmission, and/or drive train adjusts to return the equipment in a controlled manner (right diagram).

TARS Six Degrees of Freedom

Figure 1 illustrates the TARS sensor's measurement capabilities. The TARS-IMU measures six degrees of freedom, which include:

• Translational motion along the X, Y, and Z axes.
• Rotational motion around the pitch, roll, and yaw axes.

Features and Benefits

• Enhanced performance from IMU offers reporting of vehicle angular rate, acceleration, and inclination (6 degrees of freedom).
• Ruggedized PBT thermoplastic housing design enables it to be used in many demanding applications and environments (IP67 and IP69K certified).
• Advanced filtering of raw sensor data to minimize unwanted noise and vibrations, improving positioning accuracy.
• Optional metal guard for added protection.
• Supports 5 V and 9 V to 36 V vehicle power systems.
• Operating temperature of -40°C to 85°C [-40°F to 185°F].
• Reduced power consumption.
• Small form factor.

Application Example: Traction Control and Stabilization

Figure 2 demonstrates the Honeywell TARS-IMU in a Traction Control and Stabilization Application, illustrating three states of vehicle operation:

• Vehicle at Rest:

  Position data agrees with what the control system expects.

  Identifier: TARS IX Pot.:hsmpals.com IY X212087-IMU03 Y10 023 IZ

• Too Much Power Applied:

  The drive wheels begin to slip. The control system recognizes slip and limits power output or alerts the operator.

  Identifier: TARS IX Pot.:hsmpals.com IY X212087-IMU03 Y10 023 IZ

• Control Modulates Power:

  The system modulates power to minimize slip. Traction is restored, and the vehicle moves in a controlled manner, limiting potential major damage to the environment.

  Identifier: TARS IX Pot.:hsmpals.com IY X212087-IMU03 Y10 023 IZ

In this scenario, the sensor detects movement and direction of slippage, signaling the equipment control module. The system then corrects the equipment's position in real-time, making operation safer and reducing the possibility of equipment damage, landscape damage, and operator injury.

This type of assistance is becoming more prevalent as the industry moves toward fully autonomous systems. TARS-IMU can be a key component in providing and reporting essential machinery and implement data. With its six degrees of freedom, TARS-IMU reports critical movement data such as angular rate, acceleration, and inclination. Furthermore, the TARS-IMU is equipped with customizable data filters that can be tuned to reduce extraneous noise and vibration, which would otherwise distort valuable data.

The TARS-IMU utilizes a robust packaging design (IP67/IP69K), making it resilient to the rigors of the construction industry. Additionally, its wide operating temperature range of -40°C to 85°C makes it suitable for many demanding tool and implement applications.

Important Considerations

WARNING: IMPROPER INSTALLATION

• Consult with local safety agencies and their requirements when designing a machine control link, interface, and all control elements that affect safety.
• Strictly adhere to all installation instructions.
• Failure to comply with these instructions could result in death or serious injury.

Warranty and Remedy

Honeywell warrants goods of its manufacture as being free of defective materials and faulty workmanship. Honeywell's standard product warranty applies unless agreed to otherwise by Honeywell in writing; please refer to your order acknowledgement or consult your local sales office for specific warranty details. If warranted goods are returned to Honeywell during the period of coverage, Honeywell will repair or replace, at its option, without charge those items that Honeywell, in its sole discretion, finds defective. The foregoing is buyer's sole remedy and is in lieu of all other warranties, expressed or implied, including those of merchantability and fitness for a particular purpose. In no event shall Honeywell be liable for consequential, special, or indirect damages.

While Honeywell may provide application assistance personally, through its literature, and the Honeywell website, it is the customer's sole responsibility to determine the suitability of the product in the application.

Specifications may change without notice. The information supplied is believed to be accurate and reliable as of this printing. However, Honeywell assumes no responsibility for its use.

For More Information

To learn more about Honeywell's sensing and switching products:

• Call: 1-800-537-6945
• Visit: sps.honeywell.com/ast
• Email: info.sc@honeywell.com

Honeywell Advanced Sensing Technologies
830 East Arapaho Road
Richardson, TX 75081
Website: sps.honeywell.com/ast

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