The important job of a farmer requires long hours of field work. The often monotonous tasks of driving agricultural vehicles to work long rows in the field — whether it be planting, maintenance, or harvesting — is undeniably arduous and fraught with potential for human error. With advances in the development of mechanical steering devices, farmers can now program steering patterns to allow their vehicles to operate hands-free and more accurately than ever before.

The SmarTrax MD mechanical steering device applied on the steering column of a tractor allows farmers to navigate field rows hands-free.

To do so, farmers can now use a mechanical steering device that mounts to the vehicle steering column: the Raven Industries SmarTraxTM MD mechanical steering system. The SmarTrax MD is a high-torque, high-speed mechanical device that can engage up to 18 mph, and drive up to 27 mph. Navigating the system’s screen will uncover five memory locations and diagnostic LED lights for engagement and calibration direction. The 3D terrain compensation feature adjusts incoming GPS messages, compensating for roll (side-to-side tilting), pitch (front-to-rear tilting), and yaw (twisting or turning) of the machine.

A GPS antenna and a foot switch are also mounted in the vehicle. The farmer uses the steering device by driving the vehicle to set a two-point A/B line down their row; for example, with the rows when they are planting, or against the rows when spraying. After program path is set, the vehicle operator engages the mechanical steering system and it becomes hands-off. The device will steer the vehicle at its current speed and will be held to that line until the operator disengages it or it reaches the end of the row to turn around.

The RENCO rotary encoder is attached to the motor to provide vital motion control requirements.

Various types of agricultural vehicles can be steered in this manner, including tractors, combines, and self-propelled sprayers. The benefits to a farmer of a motion-controlled, hands-free vehicle are a decrease in operator fatigue and an increase in consistency. This results in improvements in operating efficiency, performance, and accuracy. Motion control and automation do not remove the operator, but gives him or her a more consistent way of running a system.

Retrofitting Equipment

The application of the SmarTrax MD mechanical steering device in the cab of agricultural vehicles allows programming of hands-free steering patterns.

To mount the SmarTrax MD system, the user must first remove the vehicle’s steering wheel. Then, using an anti-rotation bracket, the system with its slim motor is mounted onto the mechanical drive’s casing. The steering wheel is replaced at the top. It is important that the motor that is now driving the steering wheel be compact, as space is at a premium. To provide motion control feedback to the motor, a RENCO RCML 15 rotary encoder is attached to the motor. The thin profile of the RENCO encoder is important since the drive is below the steering wheel. Other advantages of the encoder include high resolution (a max line count of 5,000), low profile, 500-KHZ frequency response, Opto-Asic technology, two data channels in quadrature, and the option of three commutation channels.

The SmarTrax MD has now been in field use since July 2013. A unique benefit of this mechanical steering device is that it can easily transfer to other agricultural vehicles in a farmer’s fleet. SmarTrax MD can be used on a tractor, then removed and installed on a swather or combine. It is also ISO compatible for users who already have a compatible terminal in their cab.

The use of these technologies in the field is allowing farmers to operate in conditions that previously were impossible. Particularly notable is the use of the system in dark, windy, and dusty conditions where visual impairment is a serious problem.

This article was contributed by HEIDEN-HAIN Corp., Schaumburg, IL. For more information, Click Here .


Motion Control & Automation Technology Magazine

This article first appeared in the August, 2014 issue of Motion Control & Automation Technology Magazine.

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