Motor Class Reference

Base single-motor class. More...

#include <Motor.h>

Detailed Description

Base single-motor class.

Implements enable/disable, setting open-loop commands, PD position control, gear ratio. This class is an abstract base class, and derived classes need to implement the low-level communication with the motor driver.

Public Member Functions
virtual void	enable (bool flag)=0
	Enable the motor. More...
virtual float	getRawPosition ()=0
	Raw position read from the motor driver. More...
virtual void	sendOpenLoop (float val)=0
	Communicate a raw PWM to the motor controller. More...
void	init (float zero, int8_t direction, float gearRatio)
	Initialize motor properties. More...
float	getPosition ()
	Get position after direction and zero are taken into account. More...
float	getVelocity ()
	Get motor velocity after direction and zero are taken into account. More...
float	getOpenLoop ()
	Get the PWM duty cycle commanded to the motor. More...
void	setTorqueEstParams (float Kt, float res, float Vsource, float curLim)
	Details for torque estimate in getTorque(). Not used elsewhere. More...
float	getTorque ()
	Returns an estimate of torque assuming quasistatic. More...
void	setOpenLoop (float val)
	Set an open loop PWM command for the motor. More...
void	setGain (float Kp, float Kd)
	Set gain for position control. More...
void	setGain (float Kp)
	Set P-gain for position control (D-gain is set to 0) More...
void	setPosition (float setpoint)
	Set a desired position for the motor in radians. More...
float	update ()
	Function that communicates with the motor controller (including getting position, commanding PWM) More...
void	resetOffset ()
	Run this after you are sure there is non-garbage rawPosition data.

Static Public Attributes
static int	updateRate = 1000
	Set expected rate (Hz) at which update() will be called. More...
static float	velSmooth = 0.8
	Set smoothing factor for getVelocity() (0 is no smoothing, 1 never updates)

Inherited by BlCon34.

Member Function Documentation

virtual void Motor::enable ( bool  flag )

pure virtual

Enable the motor.

Must be implemented in derived classes

Parameters

flag	true to enable, false to disable

Implemented in BlCon34.

float Motor::getOpenLoop ( )

inline

Get the PWM duty cycle commanded to the motor.

Useful to record input when getPosition() is used

Returns

Commanded PWM in [-1, 1]

float Motor::getPosition

(

)

Get position after direction and zero are taken into account.

Returns

Position in radians between -pi and pi

virtual float Motor::getRawPosition ( )

pure virtual

Raw position read from the motor driver.

This is before the direction/zero are applied. The user should call getPosition()

Returns

Raw position in [0, 2pi]

Implemented in BlCon34.

float Motor::getTorque ( )

inline

Returns an estimate of torque assuming quasistatic.

Need to call setTorqueEstParams() beforhand

Returns

Estimate of torque in Nm

float Motor::getVelocity ( )

inline

Get motor velocity after direction and zero are taken into account.

Returns

Velocity in rad/s

void Motor::init	(	float	zero,
		int8_t	direction,
		float	gearRatio
	)

Initialize motor properties.

Parameters

zero	The zero angle (in terms of getRawPosition())
direction	One of +1 and -1 (reverses in which direction positions increase)
gearRatio	Default is 1.0 (direct drive)

virtual void Motor::sendOpenLoop ( float  val )

pure virtual

Communicate a raw PWM to the motor controller.

Must be implemented in derived classes. The user should call setOpenLoop()

Parameters

val	Raw PWM in [-1, 1]

Implemented in BlCon34.

void Motor::setGain	(	float	Kp,
		float	Kd
	)

Set gain for position control.

This must be called when setPosition() is used

Parameters

Kp	P-gain (in units of PWM / rad)
Kd	D-gain (in units of PWM / (rad/s))

void Motor::setGain ( float  Kp )

inline

Set P-gain for position control (D-gain is set to 0)

This must be called when setPosition() is used

Parameters

Kp	P-gain (in units of PWM / rad)

void Motor::setOpenLoop

(

float

val

)

Set an open loop PWM command for the motor.

These commands are only sent by update()

Parameters

val	Commanded PWM in [-1, 1]

void Motor::setPosition

(

float

setpoint

)

Set a desired position for the motor in radians.

setGain() needs to be called as well

Parameters

setpoint

Desired position in radians (relative to direction and zero set by Motor::init())

void Motor::setTorqueEstParams	(	float	Kt,
		float	res,
		float	Vsource,
		float	curLim
	)

Details for torque estimate in getTorque(). Not used elsewhere.

Parameters

Kt	in Nm/A
res	in Ohms
Vsource	in Volts

float Motor::update

(

)

Function that communicates with the motor controller (including getting position, commanding PWM)

This should be called at a more or less fixed rate (once per iteration). Change Motor::updateRate to the expected frequency that update() will be called.

Returns

Returns the corrected raw PWM sent to the motor controller

Member Data Documentation

int Motor::updateRate = 1000

static

Set expected rate (Hz) at which update() will be called.

Copyright (C) Ghost Robotics - All Rights Reserved Unauthorized copying of this file, via any medium is strictly prohibited Proprietary and confidential Written by Avik De avik@.nosp@m.ghos.nosp@m.trobo.nosp@m.tics.nosp@m..io

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The documentation for this class was generated from the following files:

• Motor.h
• Motor.cpp