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allwpilib/simulation/frc_gazebo_plugins/gyro/src/gyro.h

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C++

/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2016. All Rights Reserved. */
/* Open Source Software - may be modified and shared by FRC teams. The code */
/* must be accompanied by the FIRST BSD license file in the root directory of */
/* the project. */
/*----------------------------------------------------------------------------*/
#pragma once
#include "simulation/gz_msgs/msgs.h"
#include <gazebo/gazebo.hh>
#include <gazebo/physics/physics.hh>
#include <gazebo/transport/transport.hh>
using namespace gazebo;
/// \brief The axis about which to measure rotation.
typedef enum { Roll /*X*/, Pitch /*Y*/, Yaw /*Z*/ } ROTATION;
/**
* \brief Plugin for reading the speed and relative angle of a link.
*
* This plugin publishes the angle since last reset and the speed
* which a link is rotating about some axis to subtopics of the given
* topic every physics update. There is also a control topic that
* takes one command: "reset", which sets the current angle as zero.
*
* To add a gyro to your robot, add the following XML to your robot
* model:
*
* <plugin name="my_gyro" filename="libgyro.so">
* <link>Joint Name</link>
* <topic>~/my/topic</topic>
* <units>{degrees, radians}</units>
* </plugin>
*
* - `link`: Name of the link this potentiometer is attached to.
* - `topic`: Optional. Used as the root for subtopics. `topic`/position
* (gazebo.msgs.Float64),
* `topic`/velocity (gazebo.msgs.Float64), `topic`/control
* (gazebo.msgs.String)
* - `units`; Optional, defaults to radians.
*/
class Gyro : public ModelPlugin {
public:
/// \brief Load the gyro and configures it according to the sdf.
void Load(physics::ModelPtr model, sdf::ElementPtr sdf);
/// \brief Sends out the gyro reading each timestep.
void Update(const common::UpdateInfo& info);
private:
/// \brief Publish the angle on this topic.
std::string topic;
/// \brief Whether or not this gyro measures radians or degrees.
bool radians;
/// \brief The axis to measure rotation about.
ROTATION axis;
/// \brief The zero value of the gyro.
double zero;
/// \brief The link that this gyro measures
physics::LinkPtr link;
/// \brief Callback for handling control data
void Callback(const msgs::ConstStringPtr& msg);
/// \brief Gets the current angle, taking into account whether to
/// return radians or degrees.
double GetAngle();
/// \brief Gets the current velocity, taking into account whether to
/// return radians/second or degrees/second.
double GetVelocity();
/// \brief Limit the value to either [-180,180] or [-PI,PI]
/// depending on whether or radians or degrees are being used.
double Limit(double value);
physics::ModelPtr model; ///< \brief The model that this is attached to.
event::ConnectionPtr
updateConn; ///< \brief Pointer to the world update function.
transport::NodePtr node; ///< \brief The node we're advertising on.
transport::SubscriberPtr command_sub; ///< \brief Subscriber handle.
transport::PublisherPtr pos_pub, vel_pub; ///< \brief Publisher handles.
};