kopia lustrzana https://github.com/pimoroni/pimoroni-pico
133 wiersze
4.0 KiB
C++
133 wiersze
4.0 KiB
C++
#include <cstdio>
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#include "pico/stdlib.h"
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#include "motor2040.hpp"
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#include "button.hpp"
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#include "pid.hpp"
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/*
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A program to aid in the discovery and tuning of motor PID
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values for velocity control. It does this by commanding the
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motor to drive repeatedly between two setpoint speeds and
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plots the measured response.
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Press "Boot" to exit the program.
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*/
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using namespace motor;
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using namespace encoder;
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// The pins of the motor being profiled
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const pin_pair MOTOR_PINS = motor2040::MOTOR_A;
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// The pins of the encoder attached to the profiled motor
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const pin_pair ENCODER_PINS = motor2040::ENCODER_A;
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// The gear ratio of the motor
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constexpr float GEAR_RATIO = 50.0f;
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// The counts per revolution of the motor's output shaft
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constexpr float COUNTS_PER_REV = MMME_CPR * GEAR_RATIO;
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// The direction to spin the motor in. NORMAL_DIR (0), REVERSED_DIR (1)
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const Direction DIRECTION = NORMAL_DIR;
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// The scaling to apply to the motor's speed to match its real-world speed
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constexpr float SPEED_SCALE = 5.4f;
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// How many times to update the motor per second
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const uint UPDATES = 100;
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constexpr float UPDATE_RATE = 1.0f / (float)UPDATES;
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// The time (in seconds) after a new setpoint, to display print out motor values
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constexpr float PRINT_WINDOW = 0.25f;
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// The time (in seconds) between each new setpoint being set
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constexpr float MOVEMENT_WINDOW = 2.0f;
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// How many of the updates should be printed (i.e. 2 would be every other update)
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const uint PRINT_DIVIDER = 1;
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// Multipliers for the different printed values, so they appear nicely on the Thonny plotter
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constexpr float ACC_PRINT_SCALE = 0.01f; // Acceleration multiplier
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// How far from zero to drive the motor at, in revolutions per second
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constexpr float VELOCITY_EXTENT = 3.0f;
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// PID values
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constexpr float VEL_KP = 30.0f; // Velocity proportional (P) gain
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constexpr float VEL_KI = 0.0f; // Velocity integral (I) gain
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constexpr float VEL_KD = 0.4f; // Velocity derivative (D) gain
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// Create a motor and set its direction and speed scale
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Motor m = Motor(MOTOR_PINS, DIRECTION, SPEED_SCALE);
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// Create an encoder and set its direction and counts per rev, using PIO 0 and State Machine 0
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Encoder enc = Encoder(pio0, 0, ENCODER_PINS, PIN_UNUSED, DIRECTION, COUNTS_PER_REV, true);
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// Create the user button
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Button user_sw(motor2040::USER_SW);
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// Create PID object for velocity control
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PID vel_pid = PID(VEL_KP, VEL_KI, VEL_KD, UPDATE_RATE);
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int main() {
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stdio_init_all();
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// Initialise the motor and encoder
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m.init();
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enc.init();
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// Enable the motor
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m.enable();
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// Set the initial setpoint velocity
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vel_pid.setpoint = VELOCITY_EXTENT;
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uint update = 0;
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uint print_count = 0;
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// Continually move the motor until the user button is pressed
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while(!user_sw.raw()) {
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// Capture the state of the encoder
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Encoder::Capture capture = enc.capture();
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// Calculate the acceleration to apply to the motor to move it closer to the velocity setpoint
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float accel = vel_pid.calculate(capture.revolutions_per_second());
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// Accelerate or decelerate the motor
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m.speed(m.speed() + (accel * UPDATE_RATE));
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// Print out the current motor values and their setpoints,
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// but only for the first few updates and only every multiple
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if(update < (uint)(PRINT_WINDOW * UPDATES) && print_count == 0) {
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printf("Vel = %f, ", capture.revolutions_per_second());
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printf("Vel SP = %f, ", vel_pid.setpoint);
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printf("Accel = %f, ", accel * ACC_PRINT_SCALE);
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printf("Speed = %f\n", m.speed());
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}
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// Increment the print count, and wrap it
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print_count = (print_count + 1) % PRINT_DIVIDER;
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update++; // Move along in time
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// Have we reached the end of this time window?
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if(update >= (uint)(MOVEMENT_WINDOW * UPDATES)) {
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update = 0; // Reset the counter
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// Set the new velocity setpoint to be the inverse of the current setpoint
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vel_pid.setpoint = 0.0f - vel_pid.setpoint;
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}
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sleep_ms(UPDATE_RATE * 1000.0f);
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}
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// Disable the motor
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m.disable();
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}
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