Changes between Version 4 and Version 5 of MotorControl

Timestamp:

Feb 18, 2016, 9:58:03 PM (10 years ago)

Author:

benjialbert

Comment:

--

MotorControl

@@ -1 +1 @@
 There are many types of motors including:
-   * [https://en.wikipedia.org/wiki/DC_motor DC Motors] are usually the main motors that drive a robots wheels or tracks
-   * [http://www.jameco.com/jameco/workshop/howitworks/how-servo-motors-work.html Servo Motors] and [http://www.instructables.com/id/BYJ48-Stepper-Motor/ Stepper Motors] are used to effect fine control such as for manipulating objects.
+   * [https://en.wikipedia.org/wiki/DC_motor DC Motors] are usually the main motors that drive a robots wheels or tracks; DC motors can be powerful and are commonly used in things like motorized wheelchairs.  FRC robots, we commonly use [http://www.andymark.com/Motor-p/am-0255.htm CIM motors] and mini-CIM motors; vendors such as !AndyMark supply [http://www.andymark.com/Motors-s/260.htm many types of DC motors] that may include integrated gear boxes that convert motor speed to torque.
+   * [http://www.jameco.com/jameco/workshop/howitworks/how-servo-motors-work.html Servo Motors] and [http://www.instructables.com/id/BYJ48-Stepper-Motor/ Stepper Motors] are used to effect fine control such as for manipulating objects; they are usually much less powerful than large DC motors but can be controlled precisely.
 
+__Motor Control__
 Motors generally use electromagnets to generate physical motion such as rotating a shaft.  Electromagnets typically require much more current than a micro-controller can source directly.  To control motors, micro-controllers typically use a transistor as a valve; turning the transistor on or off requires a very small amount of current, but when turned on, the transistor can allow large amounts of current to flow through it to the motor.
 
-DC motor controllers often use 4 transistors in an [https://en.wikipedia.org/wiki/H_bridge H-Bridge] circuit; this allows the motor '''direction''' to be reversed by swapping the direction of current flow through the motor.  DC motor '''speed''' is often controlled using [http://www.electronics-tutorials.ws/blog/pulse-width-modulation.html pulse-width modulation] (PWM).  In many cases, there are dedicated integrated circuits to provide this functionality such as [http://www.gearbest.com/other-accessories/pp_218079.html Arduino Motor Shields]; and [http://playground.arduino.cc/Main/AdafruitMotorShield code libraries] to support them.
+DC motor controllers often use 4 transistors in an [https://en.wikipedia.org/wiki/H_bridge H-Bridge] circuit; this allows the motor '''direction''' to be reversed by swapping the direction of current flow through the motor.  DC motor '''speed''' is often controlled using [http://www.electronics-tutorials.ws/blog/pulse-width-modulation.html pulse-width modulation] (PWM).  In many cases, there are dedicated integrated circuits to provide this functionality such as [http://www.gearbest.com/other-accessories/pp_218079.html Arduino Motor Shields]; and [http://playground.arduino.cc/Main/AdafruitMotorShield code libraries] to support them.  FRC robots use advanced motor controllers such as the [http://www.vexrobotics.com/217-8080.html Talon SRX] which contain an H-bridge and a sophisticated Cortex ARM microcontroller that offers a wide range of capablities including CAN networking and precise control of even large DC motors via PID closed-loop control (see more on this below).
 
 Working with motors involves many considerations including protecting the motors from overheating if they are working too hard (e.g. stalled), braking control, and using the motors efficiently.  For more details about DC motor control see (see [http://www.4qd.co.uk/faq/motrat.html here])