Vehicleackermann_Drivetrain_ControllerTwistFrontSteerPID.cpp

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/*+-------------------------------------------------------------------------+
  |                       MultiVehicle simulator (libmvsim)                 |
  |                                                                         |
  | Copyright (C) 2014-2024  Jose Luis Blanco Claraco                       |
  | Copyright (C) 2017  Borys Tymchenko (Odessa Polytechnic University)     |
  | Distributed under 3-clause BSD License                                  |
  |   See COPYING                                                           |
  +-------------------------------------------------------------------------+ */
 
#include <mvsim/VehicleDynamics/VehicleAckermann_Drivetrain.h>
 
#include "xml_utils.h"
 
using namespace mvsim;
using namespace std;
 
DynamicsAckermannDrivetrain::ControllerTwistFrontSteerPID::ControllerTwistFrontSteerPID(
        DynamicsAckermannDrivetrain& veh)
        : ControllerBase(veh),
          setpoint_lin_speed(0),
          setpoint_ang_speed(0),
          KP(100),
          KI(0),
          KD(0),
          max_torque(400.0)
{
        // Get distance between wheels:
        dist_fWheels_ = veh_.wheels_info_[WHEEL_FL].y - veh_.wheels_info_[WHEEL_FR].y;
        r2f_L_ = veh_.wheels_info_[WHEEL_FL].x - veh_.wheels_info_[WHEEL_RL].x;
 
        ASSERT_(dist_fWheels_ > 0.0);
        ASSERT_(r2f_L_ > 0.0);
}
 
void DynamicsAckermannDrivetrain::ControllerTwistFrontSteerPID::control_step(
        const DynamicsAckermannDrivetrain::TControllerInput& ci,
        DynamicsAckermannDrivetrain::TControllerOutput& co)
{
        // 1st: desired steering angle:
        // --------------------------------
        if (setpoint_ang_speed == 0)
        {
                co.steer_ang = 0.0;
        }
        else
        {
                const double R = setpoint_lin_speed / setpoint_ang_speed;
                co.steer_ang = atan(r2f_L_ / R);
        }
 
        PID_.KP = KP;
        PID_.KI = KI;
        PID_.KD = KD;
        PID_.max_out = max_torque;
 
        const double vel_act = veh_.getVelocityLocalOdoEstimate().vx;
        const double vel_des = setpoint_lin_speed;
 
        // "-" because \tau<0 makes robot moves forwards.
        co.drive_torque = -PID_.compute(vel_des - vel_act, ci.context.dt);
}
 
void DynamicsAckermannDrivetrain::ControllerTwistFrontSteerPID::load_config(
        const rapidxml::xml_node<char>& node)
{
        TParameterDefinitions params;
        params["KP"] = TParamEntry("%lf", &KP);
        params["KI"] = TParamEntry("%lf", &KI);
        params["KD"] = TParamEntry("%lf", &KD);
        params["max_torque"] = TParamEntry("%lf", &max_torque);
 
        // Initial speed.
        params["V"] = TParamEntry("%lf", &this->setpoint_lin_speed);
        params["W"] = TParamEntry("%lf_deg", &this->setpoint_ang_speed);
 
        parse_xmlnode_children_as_param(node, params);
}
 
void DynamicsAckermannDrivetrain::ControllerTwistFrontSteerPID::teleop_interface(
        const TeleopInput& in, TeleopOutput& out)
{
        ControllerBase::teleop_interface(in, out);
 
        switch (in.keycode)
        {
                case 'W':
                case 'w':
                        setpoint_lin_speed += 0.1;
                        break;
 
                case 'S':
                case 's':
                        setpoint_lin_speed -= 0.1;
                        break;
 
                case 'A':
                case 'a':
                        setpoint_ang_speed += 1.0 * M_PI / 180.0;
                        break;
 
                case 'D':
                case 'd':
                        setpoint_ang_speed -= 1.0 * M_PI / 180.0;
                        break;
 
                case ' ':
                        setpoint_lin_speed = .0;
                        setpoint_ang_speed = .0;
                        break;
        };
 
        out.append_gui_lines += "[Controller=" + std::string(class_name()) + "]";
 
        if (in.js && in.js->axes.size() >= 2)
        {
                const auto& js = in.js.value();
                const float js_x = js.axes[0];
                const float js_y = js.axes[1];
 
                setpoint_lin_speed = -js_y * joyMaxLinSpeed;
                setpoint_ang_speed = -js_x * joyMaxAngSpeed;
 
                if (js.buttons.size() >= 7)
                {
                        if (js.buttons[5]) joyMaxLinSpeed *= 1.01;
                        if (js.buttons[7]) joyMaxLinSpeed /= 1.01;
 
                        if (js.buttons[4]) joyMaxAngSpeed *= 1.01;
                        if (js.buttons[6]) joyMaxAngSpeed /= 1.01;
 
                        if (js.buttons[3])      // brake
                        {
                                setpoint_lin_speed = 0;
                                setpoint_ang_speed = 0;
                        }
                }
 
                out.append_gui_lines += mrpt::format(
                        "Teleop joystick:\n"
                        "maxLinSpeed=%.03f m/s\n"
                        "maxAngSpeed=%.03f deg/s\n",
                        joyMaxLinSpeed, mrpt::RAD2DEG(joyMaxAngSpeed));
        }
        else
        {
                out.append_gui_lines +=
                        "Teleop keys:\n"
                        "w/s=forward/backward.\n"
                        "a/d=left/right.\n"
                        "spacebar=stop.\n";
        }
 
        out.append_gui_lines += mrpt::format(
                "setpoint: lin=%.03f ang=%.03f deg/s\n", setpoint_lin_speed,
                180.0 / M_PI * setpoint_ang_speed);
}