This class includes logic for PID controller. PID controller is used in this plugin to maintain the inter-vehicle gap by adjusting the speed. More...

#include <pid_controller.hpp>

Collaboration diagram for platooning_control::PIDController:

Public Member Functions
	PIDController ()
	Constructor for the PID controller class. More...

double	calculate (double setpoint, double pv)
	function to calculate control command based on setpoint and process vale More...

void	reset ()

Public Attributes
std::shared_ptr< PlatooningControlPluginConfig >	config_ = std::make_shared<PlatooningControlPluginConfig>()
	plugin config object More...

Private Attributes
double	_pre_error = 0.0

double	_integral = 0.0

Detailed Description

This class includes logic for PID controller. PID controller is used in this plugin to maintain the inter-vehicle gap by adjusting the speed.

Definition at line 27 of file pid_controller.hpp.

Constructor & Destructor Documentation

◆ PIDController()

platooning_control::PIDController::PIDController ( )

Constructor for the PID controller class.

Definition at line 22 of file pid_controller.cpp.

22{}

Member Function Documentation

◆ calculate()

double platooning_control::PIDController::calculate	(	double	setpoint,
		double	pv
	)

function to calculate control command based on setpoint and process vale

Parameters

setpoint	desired value
pv	current value

Returns: the manipulated variable given a setpoint and current process value

Definition at line 24 of file pid_controller.cpp.

                                                               {
        // Calculate error
        double error = setpoint - pv;
        RCLCPP_DEBUG_STREAM(rclcpp::get_logger("platooning_control"),"PID error: " << error);
 
        // Proportional term
        double Pout = config_->kp * error;
        RCLCPP_DEBUG_STREAM(rclcpp::get_logger("platooning_control"), "Proportional term: " << Pout);
 
        // Integral term
        _integral += error * config_->dt;
        RCLCPP_DEBUG_STREAM(rclcpp::get_logger("platooning_control"),"Integral term: " << _integral);
 
        if (_integral > config_->integrator_max){
             _integral = config_->integrator_max;
        }
        else if (_integral < config_->integrator_min){
            _integral = config_->integrator_min;
        }
        double Iout = config_->ki * _integral;
        RCLCPP_DEBUG_STREAM(rclcpp::get_logger("platooning_control"), "Iout: " << Iout);
 
        // Derivative term
        double derivative = (error - _pre_error) / config_->dt;
        RCLCPP_DEBUG_STREAM(rclcpp::get_logger("platooning_control"), "derivative term: " << derivative);
        double Dout = config_->kd * derivative;
        RCLCPP_DEBUG_STREAM(rclcpp::get_logger("platooning_control"), "Dout: " << Dout);
 
        // Calculate total output
        double output = Pout + Iout + Dout;
        RCLCPP_DEBUG_STREAM(rclcpp::get_logger("platooning_control"), "total controller output: " << output);
 
        // Restrict to max/min
        if( output > config_->max_delta_speed_per_timestep )
            output = config_->max_delta_speed_per_timestep;
        else if( output < config_->min_delta_speed_per_timestep )
            output = config_->min_delta_speed_per_timestep;
        // Save error to previous error
        _pre_error = error;
 
        return output;
 
    }

References _integral, _pre_error, and config_.

Referenced by platooning_control::PlatooningControlWorker::generate_speed().

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◆ reset()

void platooning_control::PIDController::reset ( )

Definition at line 68 of file pid_controller.cpp.

                              {
        _integral = 0.0;
        _pre_error = 0.0;
    }

References _integral, and _pre_error.

Referenced by platooning_control::PlatooningControlWorker::generate_speed().

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Member Data Documentation

◆ _integral

double platooning_control::PIDController::_integral = 0.0

private

Definition at line 66 of file pid_controller.hpp.

Referenced by calculate(), and reset().

◆ _pre_error

double platooning_control::PIDController::_pre_error = 0.0

private

Definition at line 65 of file pid_controller.hpp.

Referenced by calculate(), and reset().

◆ config_

std::shared_ptr<PlatooningControlPluginConfig> platooning_control::PIDController::config_ = std::make_shared<PlatooningControlPluginConfig>()

plugin config object

Definition at line 39 of file pid_controller.hpp.

Referenced by calculate().

The documentation for this class was generated from the following files:

platooning_control/include/platooning_control/pid_controller.hpp
platooning_control/src/pid_controller.cpp

Public Member Functions

Public Attributes

Private Attributes