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controller.cpp
351 lines (312 loc) · 13 KB
/
controller.cpp
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#include "odrive_main.h"
#include <algorithm>
#include <algorithm>
Controller::Controller(Config_t& config) :
config_(config)
{
update_filter_gains();
}
void Controller::reset() {
pos_setpoint_ = 0.0f;
vel_setpoint_ = 0.0f;
vel_integrator_current_ = 0.0f;
current_setpoint_ = 0.0f;
}
void Controller::set_error(Error error) {
error_ |= error;
axis_->error_ |= Axis::ERROR_CONTROLLER_FAILED;
}
//--------------------------------
// Command Handling
//--------------------------------
void Controller::input_pos_updated() {
input_pos_updated_ = true;
}
bool Controller::select_encoder(size_t encoder_num) {
if (encoder_num < AXIS_COUNT) {
Axis* ax = axes[encoder_num];
if (config_.setpoints_in_cpr) {
pos_estimate_src_ = &ax->encoder_.pos_cpr_;
pos_wrap_src_ = &ax->encoder_.config_.cpr;
} else {
pos_estimate_src_ = &ax->encoder_.pos_estimate_;
pos_wrap_src_ = nullptr;
}
pos_estimate_valid_src_ = &ax->encoder_.pos_estimate_valid_;
vel_estimate_src_ = &ax->encoder_.vel_estimate_;
vel_estimate_valid_src_ = &ax->encoder_.vel_estimate_valid_;
return true;
} else {
return set_error(Controller::ERROR_INVALID_LOAD_ENCODER), false;
}
}
void Controller::move_to_pos(float goal_point) {
axis_->trap_traj_.planTrapezoidal(goal_point, pos_setpoint_, vel_setpoint_,
axis_->trap_traj_.config_.vel_limit,
axis_->trap_traj_.config_.accel_limit,
axis_->trap_traj_.config_.decel_limit);
axis_->trap_traj_.t_ = 0.0f;
trajectory_done_ = false;
}
void Controller::move_incremental(float displacement, bool from_input_pos = true){
if(from_input_pos){
input_pos_ += displacement;
} else{
input_pos_ = pos_setpoint_ + displacement;
}
input_pos_updated();
}
void Controller::start_anticogging_calibration() {
// Ensure the cogging map was correctly allocated earlier and that the motor is capable of calibrating
if (axis_->error_ == Axis::ERROR_NONE) {
config_.anticogging.calib_anticogging = true;
}
}
/*
* This anti-cogging implementation iterates through each encoder position,
* waits for zero velocity & position error,
* then samples the current required to maintain that position.
*
* This holding current is added as a feedforward term in the control loop.
*/
bool Controller::anticogging_calibration(float pos_estimate, float vel_estimate) {
float pos_err = input_pos_ - pos_estimate;
if (std::abs(pos_err) <= config_.anticogging.calib_pos_threshold &&
std::abs(vel_estimate) < config_.anticogging.calib_vel_threshold) {
config_.anticogging.cogging_map[std::clamp<uint32_t>(config_.anticogging.index++, 0, 3600)] = vel_integrator_current_;
}
if (config_.anticogging.index < 3600) {
config_.control_mode = CONTROL_MODE_POSITION_CONTROL;
input_pos_ = config_.anticogging.index * axis_->encoder_.getCoggingRatio();
input_vel_ = 0.0f;
input_current_ = 0.0f;
input_pos_updated();
return false;
} else {
config_.anticogging.index = 0;
config_.control_mode = CONTROL_MODE_POSITION_CONTROL;
input_pos_ = 0.0f; // Send the motor home
input_vel_ = 0.0f;
input_current_ = 0.0f;
input_pos_updated();
anticogging_valid_ = true;
config_.anticogging.calib_anticogging = false;
return true;
}
}
void Controller::update_filter_gains() {
float bandwidth = std::min(config_.input_filter_bandwidth, 0.25f * current_meas_hz);
input_filter_ki_ = 2.0f * bandwidth; // basic conversion to discrete time
input_filter_kp_ = 0.25f * (input_filter_ki_ * input_filter_ki_); // Critically damped
}
static float limitVel(const float vel_limit, const float vel_estimate, const float vel_gain, const float Iq) {
float Imax = (vel_limit - vel_estimate) * vel_gain;
float Imin = (-vel_limit - vel_estimate) * vel_gain;
return std::clamp(Iq, Imin, Imax);
}
bool Controller::update(float* current_setpoint_output) {
float* pos_estimate_src = (pos_estimate_valid_src_ && *pos_estimate_valid_src_)
? pos_estimate_src_ : nullptr;
float* vel_estimate_src = (vel_estimate_valid_src_ && *vel_estimate_valid_src_)
? vel_estimate_src_ : nullptr;
// Calib_anticogging is only true when calibration is occurring, so we can't block anticogging_pos
float anticogging_pos = axis_->encoder_.pos_estimate_ / axis_->encoder_.getCoggingRatio();
if (config_.anticogging.calib_anticogging) {
if (!axis_->encoder_.pos_estimate_valid_ || !axis_->encoder_.vel_estimate_valid_) {
set_error(ERROR_INVALID_ESTIMATE);
return false;
}
// non-blocking
anticogging_calibration(axis_->encoder_.pos_estimate_, axis_->encoder_.vel_estimate_);
}
// TODO also enable circular deltas for 2nd order filter, etc.
if (pos_wrap_src_) {
float cpr = *pos_wrap_src_;
// Keep pos setpoint from drifting
input_pos_ = fmodf_pos(input_pos_, cpr);
}
// Update inputs
switch (config_.input_mode) {
case INPUT_MODE_INACTIVE: {
// do nothing
} break;
case INPUT_MODE_PASSTHROUGH: {
pos_setpoint_ = input_pos_;
vel_setpoint_ = input_vel_;
current_setpoint_ = input_current_;
} break;
case INPUT_MODE_VEL_RAMP: {
float max_step_size = std::abs(current_meas_period * config_.vel_ramp_rate);
float full_step = input_vel_ - vel_setpoint_;
float step = std::clamp(full_step, -max_step_size, max_step_size);
vel_setpoint_ += step;
current_setpoint_ = (step / current_meas_period) * config_.inertia;
} break;
case INPUT_MODE_CURRENT_RAMP: {
float max_step_size = std::abs(current_meas_period * config_.current_ramp_rate);
float full_step = input_current_ - current_setpoint_;
float step = std::clamp(full_step, -max_step_size, max_step_size);
current_setpoint_ += step;
} break;
case INPUT_MODE_POS_FILTER: {
// 2nd order pos tracking filter
float delta_pos = input_pos_ - pos_setpoint_; // Pos error
float delta_vel = input_vel_ - vel_setpoint_; // Vel error
float accel = input_filter_kp_*delta_pos + input_filter_ki_*delta_vel; // Feedback
current_setpoint_ = accel * config_.inertia; // Accel
vel_setpoint_ += current_meas_period * accel; // delta vel
pos_setpoint_ += current_meas_period * vel_setpoint_; // Delta pos
} break;
case INPUT_MODE_MIRROR: {
if (config_.axis_to_mirror < AXIS_COUNT) {
pos_setpoint_ = axes[config_.axis_to_mirror]->encoder_.pos_estimate_ * config_.mirror_ratio;
vel_setpoint_ = axes[config_.axis_to_mirror]->encoder_.vel_estimate_ * config_.mirror_ratio;
} else {
set_error(ERROR_INVALID_MIRROR_AXIS);
return false;
}
} break;
// case INPUT_MODE_MIX_CHANNELS: {
// // NOT YET IMPLEMENTED
// } break;
case INPUT_MODE_TRAP_TRAJ: {
if(input_pos_updated_){
move_to_pos(input_pos_);
input_pos_updated_ = false;
}
// Avoid updating uninitialized trajectory
if (trajectory_done_)
break;
if (axis_->trap_traj_.t_ > axis_->trap_traj_.Tf_) {
// Drop into position control mode when done to avoid problems on loop counter delta overflow
config_.control_mode = CONTROL_MODE_POSITION_CONTROL;
pos_setpoint_ = input_pos_;
vel_setpoint_ = 0.0f;
current_setpoint_ = 0.0f;
trajectory_done_ = true;
} else {
TrapezoidalTrajectory::Step_t traj_step = axis_->trap_traj_.eval(axis_->trap_traj_.t_);
pos_setpoint_ = traj_step.Y;
vel_setpoint_ = traj_step.Yd;
current_setpoint_ = traj_step.Ydd * config_.inertia;
axis_->trap_traj_.t_ += current_meas_period;
}
anticogging_pos = pos_setpoint_; // FF the position setpoint instead of the pos_estimate
} break;
default: {
set_error(ERROR_INVALID_INPUT_MODE);
return false;
}
}
// Position control
// TODO Decide if we want to use encoder or pll position here
float gain_scheduling_multiplier = 1.0f;
float vel_des = vel_setpoint_;
if (config_.control_mode >= CONTROL_MODE_POSITION_CONTROL) {
float pos_err;
if (!pos_estimate_src) {
set_error(ERROR_INVALID_ESTIMATE);
return false;
}
if (pos_wrap_src_) {
float cpr = *pos_wrap_src_;
// Keep pos setpoint from drifting
pos_setpoint_ = fmodf_pos(pos_setpoint_, cpr);
// Circular delta
pos_err = pos_setpoint_ - *pos_estimate_src;
pos_err = wrap_pm(pos_err, 0.5f * cpr);
} else {
pos_err = pos_setpoint_ - *pos_estimate_src;
}
vel_des += config_.pos_gain * pos_err;
// V-shaped gain shedule based on position error
float abs_pos_err = std::abs(pos_err);
if (config_.enable_gain_scheduling && abs_pos_err <= config_.gain_scheduling_width) {
gain_scheduling_multiplier = abs_pos_err / config_.gain_scheduling_width;
}
}
// Velocity limiting
float vel_lim = config_.vel_limit;
if (config_.enable_vel_limit) {
vel_des = std::clamp(vel_des, -vel_lim, vel_lim);
}
// Check for overspeed fault (done in this module (controller) for cohesion with vel_lim)
if (config_.enable_overspeed_error) { // 0.0f to disable
if (!vel_estimate_src) {
set_error(ERROR_INVALID_ESTIMATE);
return false;
}
if (std::abs(*vel_estimate_src) > config_.vel_limit_tolerance * vel_lim) {
set_error(ERROR_OVERSPEED);
return false;
}
}
// TODO: Change to controller working in torque units
// Torque per amp gain scheduling (ACIM)
float vel_gain = config_.vel_gain;
float vel_integrator_gain = config_.vel_integrator_gain;
if (axis_->motor_.config_.motor_type == Motor::MOTOR_TYPE_ACIM) {
float effective_flux = axis_->motor_.current_control_.acim_rotor_flux;
float minflux = axis_->motor_.config_.acim_gain_min_flux;
if (fabsf(effective_flux) < minflux)
effective_flux = std::copysignf(minflux, effective_flux);
vel_gain /= effective_flux;
vel_integrator_gain /= effective_flux;
// TODO: also scale the integral value which is also changing units.
// (or again just do control in torque units)
}
// Velocity control
float Iq = current_setpoint_;
// Anti-cogging is enabled after calibration
// We get the current position and apply a current feed-forward
// ensuring that we handle negative encoder positions properly (-1 == motor->encoder.encoder_cpr - 1)
if (anticogging_valid_ && config_.anticogging.anticogging_enabled) {
Iq += config_.anticogging.cogging_map[std::clamp(mod((int)anticogging_pos, 3600), 0, 3600)];
}
float v_err = 0.0f;
if (config_.control_mode >= CONTROL_MODE_VELOCITY_CONTROL) {
if (!vel_estimate_src) {
set_error(ERROR_INVALID_ESTIMATE);
return false;
}
v_err = vel_des - *vel_estimate_src;
Iq += (vel_gain * gain_scheduling_multiplier) * v_err;
// Velocity integral action before limiting
Iq += vel_integrator_current_;
}
// Velocity limiting in current mode
if (config_.control_mode < CONTROL_MODE_VELOCITY_CONTROL && config_.enable_current_mode_vel_limit) {
if (!vel_estimate_src) {
set_error(ERROR_INVALID_ESTIMATE);
return false;
}
Iq = limitVel(config_.vel_limit, *vel_estimate_src, vel_gain, Iq);
}
// Current limiting
// TODO: Change to controller working in torque units
// and get the torque limits from a function of the motor
bool limited = false;
float Ilim = axis_->motor_.effective_current_lim();
if (Iq > Ilim) {
limited = true;
Iq = Ilim;
}
if (Iq < -Ilim) {
limited = true;
Iq = -Ilim;
}
// Velocity integrator (behaviour dependent on limiting)
if (config_.control_mode < CONTROL_MODE_VELOCITY_CONTROL) {
// reset integral if not in use
vel_integrator_current_ = 0.0f;
} else {
if (limited) {
// TODO make decayfactor configurable
vel_integrator_current_ *= 0.99f;
} else {
vel_integrator_current_ += ((vel_integrator_gain * gain_scheduling_multiplier) * current_meas_period) * v_err;
}
}
if (current_setpoint_output) *current_setpoint_output = Iq;
return true;
}