kopia lustrzana https://github.com/pimoroni/pimoroni-pico
126 wiersze
3.6 KiB
C++
126 wiersze
3.6 KiB
C++
#include <cstdio>
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#include "pico/stdlib.h"
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#include "inventor.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 position control. It does this by commanding the
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motor to move repeatedly between two setpoint angles and
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plots the measured response.
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Press "User" to exit the program.
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*/
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using namespace inventor;
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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 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 SPD_PRINT_SCALE = 10.0f; // Driving Speed multipler
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// How far from zero to move the motor, in degrees
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constexpr float POSITION_EXTENT = 90.0f;
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// PID values
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constexpr float POS_KP = 0.14f; // Position proportional (P) gain
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constexpr float POS_KI = 0.0f; // Position integral (I) gain
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constexpr float POS_KD = 0.002f; // Position derivative (D) gain
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// Create a new Inventor2040W
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Inventor2040W board(GEAR_RATIO);
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// Create PID object for position control
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PID pos_pid = PID(POS_KP, POS_KI, POS_KD, UPDATE_RATE);
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int main() {
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stdio_init_all();
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// Attempt to initialise the board
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if(board.init()) {
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// Access the motor and encoder from Inventor
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Motor& m = board.motors[MOTOR_A];
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Encoder& enc = board.encoders[MOTOR_A];
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//# Set the motor's speed scale
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m.speed_scale(SPEED_SCALE);
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// Set the motor and encoder's direction
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m.direction(DIRECTION);
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enc.direction(DIRECTION);
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// Enable the motor
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m.enable();
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// Set the initial setpoint position
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pos_pid.setpoint = POSITION_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(!board.switch_pressed()) {
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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 velocity to move the motor closer to the position setpoint
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float vel = pos_pid.calculate(capture.degrees(), capture.degrees_per_second());
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// Set the new motor driving speed
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m.speed(vel);
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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("Pos = %f, ", capture.degrees());
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printf("Pos SP = %f, ", pos_pid.setpoint);
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printf("Speed = %f\n", m.speed() * SPD_PRINT_SCALE);
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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 position setpoint to be the inverse of the current setpoint
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pos_pid.setpoint = 0.0f - pos_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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}
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