94 lines
3.9 KiB
C++
94 lines
3.9 KiB
C++
/*
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Copyright (c) 2016, Juan Jimeno
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Source: http://research.ijcaonline.org/volume113/number3/pxc3901586.pdf
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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Neither the name of nor the names of its contributors may be used to
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endorse or promote products derived from this software without specific
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prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORTPPIPI (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "Kinematics.h"
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#define MOTOR_MAX_RPM 90 // motor's maximum rpm
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#define WHEEL_DIAMETER 0.2 // robot's wheel diameter expressed in meters
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#define FR_WHEEL_DISTANCE 0.6 // distance between front wheel and rear wheel
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#define LR_WHEEL_DISTANCE 0.5 // distance between left wheel and right wheel
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#define PWM_BITS 8 // microcontroller's PWM pin resolution. Arduino Uno/Mega Teensy is using 8 bits(0-255)
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Kinematics kinematics(MOTOR_MAX_RPM, WHEEL_DIAMETER, FR_WHEEL_DISTANCE, LR_WHEEL_DISTANCE, PWM_BITS);
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void setup()
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{
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Serial.begin(9600);
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}
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void loop()
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{
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Kinematics::output rpm;
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//simulated required velocities
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float linear_vel_x = 1; // 1 m/s
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float linear_vel_y = 0; // 0 m/s
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float angular_vel_z = 1; // 1 m/s
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//given the required velocities for the robot, you can calculate the rpm required for each motor
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rpm = kinematics.getRPM(linear_vel_x, linear_vel_y, angular_vel_z);
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Serial.print(" FRONT LEFT MOTOR: ");
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// Assuming you have an encoder for each wheel, you can pass this RPM value to a PID controller
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// as a setpoint and your encoder data as a feedback.
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Serial.print(rpm.motor1);
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Serial.print(" FRONT RIGHT MOTOR: ");
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Serial.print(rpm.motor2);
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Serial.print(" REAR LEFT MOTOR: ");
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Serial.print(rpm.motor3);
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Serial.print(" REAR RIGHT MOTOR: ");
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Serial.println(rpm.motor4);
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delay(5000);
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// This is a simulated feedback from each motor. We'll just pass the calculated rpm above for demo's sake.
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// In a live robot, these should be replaced with real RPM values derived from encoder.
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int motor1_feedback = rpm.motor1; //in rpm
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int motor2_feedback = rpm.motor2; //in rpm
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int motor3_feedback = rpm.motor3; //in rpm
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int motor4_feedback = rpm.motor4; //in rpm
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Kinematics::velocities vel;
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// Now given the RPM from each wheel, you can calculate the linear and angular velocity of the robot.
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// This is useful if you want to create an odometry data (dead reckoning)
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vel = kinematics.getVelocities(motor1_feedback, motor2_feedback, motor3_feedback, motor4_feedback);
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Serial.print(" VEL X: ");
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Serial.print(vel.linear_x, 4);
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Serial.print(" VEL_Y: ");
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Serial.print(vel.linear_y, 4);
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Serial.print(" ANGULAR_Z: ");
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Serial.println(vel.angular_z, 4);
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Serial.println("");
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}
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