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Topic: Motor Control - Configuring Vehicular Acceleration (Read 1 time) previous topic - next topic


May 21, 2012, 11:20 pm Last Edit: May 21, 2012, 11:42 pm by Burnie Reason: 1

I am assisting in a project involving 4 robotic vehicles utilizing the Arduino MEGA + Ardumoto Shield + XBee Wireless Communications Shield, and consisting of two 12V DC Gearhead Motors driving two wheels in the back, and one guide wheel in the front.  The set of robots are for research for safe coordination of multiple autonomous vehicles.

I should note that the motors are Pololu 12V DC, 350 RPM.
• Gear ratio: 29:1
• Free-run speed @ 6V: 175 rpm
• Free-run current @ 6V: 250 mA
• Stall current @ 6V: 2500 mA
• Stall torque @ 6V: 55 oz·in

I am attempting to greatly reduce the slip action as the robot runs it's given program.  Even for a most basic program aimed at running the robots in a straight line, the robots have the characteristic of jerking once they register the assigned program.  

Controlling the acceleration parameters seems to be the best way to address this issue.  Right now, I realize the robot is NOT being controlled by the motor dynamics, and only by the robots kinematics -- specifically, it's velocity.  If I could adjust the torque settings of the motors directly by programming the Arduino, I believe the robots would accelerate much more smoothly into it's constant velocity.  

Is there a way to tap into the motor dynamics through the Arduino and configure with the motor settings?  

If I am leaving out key details, let me know and I will be more specific.

I am fairly new to this and would appreciate any guidance the Arduino community can provide.

Thank you,



Motors don't have settings.  What do you mean by "acceleration parameters"?   How are you controlling the motors - on/off or PWM?

You can ramp up the PWM drive at a rate of your choice to accelerate smoothly if you are using PWM - you can't directly control the current though, so if you want control of the torque you'll need to measure the motor current (proportional to torque for a DC motor) and use feedback.
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