mirror of https://github.com/ArduPilot/ardupilot
59 lines
2.1 KiB
C++
59 lines
2.1 KiB
C++
#include "mode.h"
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#include "Rover.h"
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void ModeSteering::update()
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{
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float desired_steering, desired_throttle;
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get_pilot_desired_steering_and_throttle(desired_steering, desired_throttle);
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// convert pilot throttle input to desired speed (up to twice the cruise speed)
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const float target_speed = desired_throttle * 0.01f * calc_speed_max(g.speed_cruise, g.throttle_cruise * 0.01f);
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// get speed forward
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float speed;
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if (!attitude_control.get_forward_speed(speed)) {
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// no valid speed so stop
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g2.motors.set_throttle(0.0f);
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g2.motors.set_steering(0.0f);
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return;
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}
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// determine if pilot is requesting pivot turn
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bool is_pivot_turning = g2.motors.have_skid_steering() && is_zero(target_speed) && (!is_zero(desired_steering));
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// In steering mode we control lateral acceleration directly.
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// For pivot steering vehicles we use the TURN_MAX_G parameter
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// For regular steering vehicles we use the maximum lateral acceleration at full steering lock for this speed: V^2/R where R is the radius of turn.
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float max_g_force;
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if (is_pivot_turning) {
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max_g_force = g.turn_max_g * GRAVITY_MSS;
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} else {
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max_g_force = speed * speed / MAX(g2.turn_radius, 0.1f);
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}
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// constrain to user set TURN_MAX_G
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max_g_force = constrain_float(max_g_force, 0.1f, g.turn_max_g * GRAVITY_MSS);
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// convert pilot steering input to desired lateral acceleration
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float desired_lat_accel = max_g_force * (desired_steering / 4500.0f);
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// reverse target lateral acceleration if backing up
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bool reversed = false;
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if (is_negative(target_speed)) {
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reversed = true;
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desired_lat_accel = -desired_lat_accel;
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}
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// mark us as in_reverse when using a negative throttle
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rover.set_reverse(reversed);
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// run speed to throttle output controller
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if (is_zero(target_speed) && !is_pivot_turning) {
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stop_vehicle();
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} else {
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// run lateral acceleration to steering controller
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calc_steering_from_lateral_acceleration(desired_lat_accel, reversed);
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calc_throttle(target_speed, false);
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}
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}
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