# Ignition Gazebo

## API Reference

6.6.0
DiffDrive Class Reference

Differential drive controller which can be attached to a model with any number of left and right wheels. More...

#include <DiffDrive.hh>

## Public Member Functions

DiffDrive ()
Constructor. More...

~DiffDrive () override=default
Destructor. More...

void Configure (const Entity &_entity, const std::shared_ptr< const sdf::Element > &_sdf, EntityComponentManager &_ecm, EventManager &_eventMgr) override
Configure the system. More...

void PostUpdate (const UpdateInfo &_info, const EntityComponentManager &_ecm) override

void PreUpdate (const UpdateInfo &_info, EntityComponentManager &_ecm) override

Public Member Functions inherited from System
System ()=default
Constructor. More...

virtual ~System ()=default
Destructor. More...

## Detailed Description

Differential drive controller which can be attached to a model with any number of left and right wheels.

# System Parameters

<left_joint>: Name of a joint that controls a left wheel. This element can appear multiple times, and must appear at least once.

<right_joint>: Name of a joint that controls a right wheel. This element can appear multiple times, and must appear at least once.

<wheel_separation>: Distance between wheels, in meters. This element is optional, although it is recommended to be included with an appropriate value. The default value is 1.0m.

<wheel_radius>: Wheel radius in meters. This element is optional, although it is recommended to be included with an appropriate value. The default value is 0.2m.

<odom_publish_frequency>: Odometry publication frequency. This element is optional, and the default value is 50Hz.

<topic>: Custom topic that this system will subscribe to in order to receive command velocity messages. This element if optional, and the default value is /model/{name_of_model}/cmd_vel.

<odom_topic>: Custom topic on which this system will publish odometry messages. This element if optional, and the default value is /model/{name_of_model}/odometry.

<tf_topic>: Custom topic on which this system will publish the transform from frame_id to child_frame_id. This element if optional, and the default value is /model/{name_of_model}/tf.

<frame_id>: Custom frame_id field that this system will use as the origin of the odometry transform in both the <tf_topic> ignition.msgs.Pose_V message and the <odom_topic> ignition.msgs.Odometry message. This element if optional, and the default value is {name_of_model}/odom.

<child_frame_id>: Custom child_frame_id that this system will use as the target of the odometry trasnform in both the <tf_topic> ignition.msgs.Pose_V message and the <odom_topic> ignition.msgs.Odometry message. This element if optional, and the default value is {name_of_model}/{name_of_link}.

<min_velocity>: Sets both the minimum linear and minimum angular velocity.

<max_velocity>: Sets both the maximum linear and maximum angular velocity.

<min_acceleration>: Sets both the minimum linear and minimum angular acceleration.

<max_acceleration>: Sets both the maximum linear and maximum angular acceleration.

<min_jerk>: Sets both the minimum linear and minimum angular jerk.

<max_jerk>: Sets both the maximum linear and maximum angular jerk.

<min_linear_velocity>: Sets the minimum linear velocity. Overrides <min_velocity> if set.

<max_linear_velocity>: Sets the maximum linear velocity. Overrides <max_velocity> if set.

<min_angular_velocity>: Sets the minimum angular velocity. Overrides <min_velocity> if set.

<max_angular_velocity>: Sets the maximum angular velocity. Overrides <max_velocity> if set.

<min_linear_acceleration>: Sets the minimum linear acceleration. Overrides <min_acceleration> if set.

<max_linear_acceleration>: Sets the maximum linear acceleration. Overrides <max_acceleration> if set.

<min_angular_acceleration>: Sets the minimum angular acceleration. Overrides <min_acceleration> if set.

<max_angular_acceleration>: Sets the maximum angular acceleration. Overrides <max_acceleration> if set.

<min_linear_jerk>: Sets the minimum linear jerk. Overrides <min_jerk> if set.

<max_linear_jerk>: Sets the maximum linear jerk. Overrides <max_jerk> if set.

<min_angular_jerk>: Sets the minimum angular jerk. Overrides <min_jerk> if set.

<max_angular_jerk>: Sets the maximum angular jerk. Overrides <max_jerk> if set.

## ◆ DiffDrive()

 DiffDrive ( )

Constructor.

## ◆ ~DiffDrive()

 ~DiffDrive ( )
overridedefault

Destructor.

## ◆ Configure()

 void Configure ( const Entity & _entity, const std::shared_ptr< const sdf::Element > & _sdf, EntityComponentManager & _ecm, EventManager & _eventMgr )
overridevirtual

Configure the system.

Parameters
 [in] _entity The entity this plugin is attached to. [in] _sdf The SDF Element associated with this system plugin. [in] _ecm The EntityComponentManager of the given simulation instance. [in] _eventMgr The EventManager of the given simulation instance.

Implements ISystemConfigure.

## ◆ PostUpdate()

 void PostUpdate ( const UpdateInfo & _info, const EntityComponentManager & _ecm )
overridevirtual

Implements ISystemPostUpdate.

## ◆ PreUpdate()

 void PreUpdate ( const UpdateInfo & _info, EntityComponentManager & _ecm )
overridevirtual

Implements ISystemPreUpdate.

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