VehicleAckermann_Drivetrain.h

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/*+-------------------------------------------------------------------------+
  |                       MultiVehicle simulator (libmvsim)                 |
  |                                                                         |
  | Copyright (C) 2014-2020  Jose Luis Blanco Claraco                       |
  | Copyright (C) 2017  Borys Tymchenko (Odessa Polytechnic University)     |
  | Distributed under 3-clause BSD License                                  |
  |   See COPYING                                                           |
  +-------------------------------------------------------------------------+ */

#pragma once

#include <mrpt/img/TColor.h>
#include <mvsim/PID_Controller.h>
#include <mvsim/VehicleBase.h>

namespace mvsim
{
class DynamicsAckermannDrivetrain : public VehicleBase
{
        DECLARES_REGISTER_VEHICLE_DYNAMICS(DynamicsAckermannDrivetrain)
   public:
        // Wheels: [0]:rear-left, [1]:rear-right, [2]: front-left, [3]: front-right
        enum
        {
                WHEEL_RL = 0,
                WHEEL_RR = 1,
                WHEEL_FL = 2,
                WHEEL_FR = 3
        };

        enum DifferentialType
        {
                DIFF_OPEN_FRONT = 0,
                DIFF_OPEN_REAR = 1,
                DIFF_OPEN_4WD = 2,

                DIFF_TORSEN_FRONT = 3,
                DIFF_TORSEN_REAR = 4,
                DIFF_TORSEN_4WD = 5,

                DIFF_MAX
        };

        DynamicsAckermannDrivetrain(World* parent);

        double getMaxSteeringAngle() const { return m_max_steer_ang; }
        void setMaxSteeringAngle(double val) { m_max_steer_ang = val; }
        struct TControllerInput
        {
                TSimulContext context;
        };
        struct TControllerOutput
        {
                double drive_torque;
                double steer_ang;  
                TControllerOutput() : drive_torque(0), steer_ang(0) {}
        };

        typedef ControllerBaseTempl<DynamicsAckermannDrivetrain> ControllerBase;
        typedef std::shared_ptr<ControllerBase> ControllerBasePtr;

        class ControllerRawForces : public ControllerBase
        {
           public:
                ControllerRawForces(DynamicsAckermannDrivetrain& veh);
                static const char* class_name() { return "raw"; }
                double setpoint_wheel_torque, setpoint_steer_ang;
                virtual void control_step(
                        const DynamicsAckermannDrivetrain::TControllerInput& ci,
                        DynamicsAckermannDrivetrain::TControllerOutput& co) override;
                virtual void load_config(const rapidxml::xml_node<char>& node) override;
                virtual void teleop_interface(
                        const TeleopInput& in, TeleopOutput& out) override;
        };

        class ControllerTwistFrontSteerPID : public ControllerBase
        {
           public:
                ControllerTwistFrontSteerPID(DynamicsAckermannDrivetrain& veh);
                static const char* class_name() { return "twist_front_steer_pid"; }
                double setpoint_lin_speed,
                        setpoint_ang_speed;      
                virtual void control_step(
                        const DynamicsAckermannDrivetrain::TControllerInput& ci,
                        DynamicsAckermannDrivetrain::TControllerOutput& co) override;
                virtual void load_config(const rapidxml::xml_node<char>& node) override;
                virtual void teleop_interface(
                        const TeleopInput& in, TeleopOutput& out) override;

                double KP, KI, KD;      
                double max_torque;      

                // See base docs.
                virtual bool setTwistCommand(const double vx, const double wz) override
                {
                        setpoint_lin_speed = vx;
                        setpoint_ang_speed = wz;
                        return true;
                }

           private:
                double m_dist_fWheels, m_r2f_L;
                PID_Controller m_PID;
        };

        class ControllerFrontSteerPID : public ControllerBase
        {
           public:
                ControllerFrontSteerPID(DynamicsAckermannDrivetrain& veh);
                static const char* class_name() { return "front_steer_pid"; }
                double setpoint_lin_speed, setpoint_steer_ang;  
                virtual void control_step(
                        const DynamicsAckermannDrivetrain::TControllerInput& ci,
                        DynamicsAckermannDrivetrain::TControllerOutput& co) override;
                virtual void load_config(const rapidxml::xml_node<char>& node) override;
                virtual void teleop_interface(
                        const TeleopInput& in, TeleopOutput& out) override;

                double KP, KI, KD;      
                double max_torque;      
           private:
                ControllerTwistFrontSteerPID m_twist_control;
                double m_r2f_L;
        };

        const ControllerBasePtr& getController() const { return m_controller; }
        ControllerBasePtr& getController() { return m_controller; }
        virtual ControllerBaseInterface* getControllerInterface() override
        {
                return m_controller.get();
        }
  // end controllers

        virtual mrpt::math::TTwist2D getVelocityLocalOdoEstimate() const override;

        void computeFrontWheelAngles(
                const double desired_equiv_steer_ang, double& out_fl_ang,
                double& out_fr_ang) const;

        void computeDiffTorqueSplit(
                const double w1, const double w2, const double diffBias,
                const double defaultSplitRatio, double& t1, double& t2);

   protected:
        // See base class docs
        virtual void dynamics_load_params_from_xml(
                const rapidxml::xml_node<char>* xml_node) override;
        // See base class doc
        virtual void invoke_motor_controllers(
                const TSimulContext& context,
                std::vector<double>& out_force_per_wheel) override;

   private:
        ControllerBasePtr m_controller;  

        double m_max_steer_ang;  

        DifferentialType m_diff_type;

        double m_FrontRearSplit;
        double m_FrontLRSplit;
        double m_RearLRSplit;

        double m_FrontRearBias;
        double m_FrontLRBias;
        double m_RearLRBias;
};
}  // namespace mvsim