Axis Control : OTF Motion Profile Controller

Flexible abstract classes for single and multi-axis speed + acceleration + jerk control. (Jerk In Progress)

Installation

git clone https://github.com/NWalker4483/AxisControl
cd AxisControl
mkdir build
sudo make install

or

Add zip to Arduino IDE Libaries Folder

Usage

MultiAxis<num_axis>

Meant for when a change in the speed of one motor can affect the speed of multiple axes. So the speed of each axis must be managed simultaneously

This class will instantiate a list of Axis objects automatically and then the corresponding override functions will allow the same level of control but with the consideration that changes on one Axis may affect other axes.

#include "axis_control/multi_axis.h"

class MyRobot: MultiAxis<3>{

    PID motor[3];
    joint_sensor[3];

unsigned int getMillis() override {
    /* If the time passed since isn't passed into the run function then this allows the
object to grab how many units of time passed since the program started and compute speed + acceleration.
            e.g millis();
*/
};

void computeAxisPositions(double *axis_positions) override {
    /* this function is passed a pointer in which to store the current position of each controlled axis in order */
    for(int i = 0; i < 3; i++) *(axis_positions[i]) = joint_sensor[i].value;
};

void updateMotorSpeeds(double *axis_speeds) override {
    /* this function is passed a pointer to all of the current target speeds that each axis should attempt to achieve.
The instantaneous motor speeds should then be calculated by the user and applied for proper control*/
    // Do linear algebra to convert speeds
    motor[i].setpoint = axis_speeds[i] * reductions;
};

void pollMotors() override {
    /* this function is meant to stand in the place of anything that needs to be called as often as
possible for the motors to move at an appropriate speed

    e.g AxisStepper::runSpeed()
*/
   for(int i = 0; i < 3; i++) motor[i].update(axis[i].real_speed);
};
}

MyRobot.setLimitMode(0);// Default: Limit Speed

// Set all joint speeds at once
MyRobot.setTargetSpeed(5)// deg/s

double home_pose[3] = {90, 0, 90};
double second_pose[3] = {30, 45, 10};
double jojo_pose[3] = {71, 24, -45};

MyRobot.moveAllTo(home_pose);
MyRobot.runToPositions();

MyRobot.setLimitMode(1); // Limit Acceleration

// Set each joint individually
MyRobot.axis[0].setTargetAcceleration(2.5) // deg/s^2
MyRobot.axis[1].setTargetAcceleration(1) // deg/s^2
MyRobot.axis[2].setTargetAcceleration(3) // deg/s^2

MyRobot.axis[0].moveTo(second_pose[0]);
MyRobot.axis[1].moveTo(second_pose[1]);
MyRobot.axis[2].moveTo(second_pose[2]);
while (MyRobot.run());

MyRobot.setLimitMode(2);
// Limit Jerk NOTE: Work in progress and lots of float math so mileage may vary on arduinos

MyRobot.setTargetJerk(.5) // deg/s^2/s=

MyRobot.moveAllTo(jojo_pose);
MyRobot.runToPositions();

Axis

Used for controlling a single axis at a time

/*
 These functions work basically the same as the ones I described above but for a single access it's not necessary to try and override these if you just want to use the MultiAxis class.
*/
virtual unsigned int getMillis();
virtual void computePosition();
virtual void updateMotorSpeed(double *axis_speed);
virtual void pollMotor() {};