一、提要

ROS-control是ROS的重要概念，而 ROS-control是通过PR2开发而产生的，因此，实质上，吃透PR2实质就是吃透了ROS-control；本篇主要阐明ROS-control的消息；

ROS-control的基础是pr2，PR2（Personal Robot 2，个人机器人2代）是Willow Garage公司设计的机器人平台，其中数字2代表第二代机器人。本文将介绍在ROS中的pr2机制，以及对应的接口开发原理。

二、pr2的六个关键

2.1 Pr2的六个关键知识点如下

pr2_controller_interface：实时控制器的 C++ 接口
pr2_controller_manager：允许您在实时循环中运行和管理多个控制器的基础架构
pr2_hardware_interface：PR2 硬件的 C++ 接口，包含执行器、压力传感器、加速度计、数字输出和投影仪接口。
pr2_mechanism_model：力控机器人的模型，基于 urdf 机器人描述格式。
pr2_mechanism_msgs：用于与实时控制回路通信的消息，以及包含实时控制器、关节和执行器状态的消息。
realtime_tools：实时发布到 ROS 主题的工具。

本篇主要探讨pr2_mechanism_msgs和realtime_tools；

三、关于pr2_mechanism_msgs

这个包定义了用于与实时控制循环通信的服务。它还定义了表示实时控制器、关节和执行器状态的消息。

ROS Message / Service / Action Types

ROS Message Types	ROS Service Types	ROS Action Types
ActuatorStatistics ControllerStatistics JointStatistics MechanismStatistics	ListControllerTypes ListControllers LoadController ReloadControllerLibraries SwitchController UnloadController	SwitchController

四、ROS Message Types

4.1 pr2_mechanism_msgs/ActuatorStatistics

此消息包含 pr2 机器人上执行器的状态。执行器包含电机和编码器，通过transmission传输到关节。

# actuator的名称
string name

# ethercat 链中 MCB 的序列号。
# 链中的第一个设备的 deviced_id 为零
int32 device_id

# 测量此执行器状态的时间

time timestamp

# the encoder position, represented by the number of encoder ticks
int32 encoder_count

# The angular offset (in radians) that is added to the encoder reading,
# to get to the position of the actuator. This number is computed when the referece
# sensor is triggered during the calibration phase
float64 encoder_offset

# the encoder position in radians
float64 position

# the encoder velocity in encoder ticks per second
float64 encoder_velocity

# the encoder velocity in radians per second
float64 velocity

# the value of the calibration reading: low (false) or high (true)
bool calibration_reading

# bool to indicate if the joint already triggered the rising/falling edge of the reference sensor
bool calibration_rising_edge_valid
bool calibration_falling_edge_valid

# the encoder position when the last rising/falling edge was observed.
# only read this value when the calibration_rising/falling_edge_valid is true
float64 last_calibration_rising_edge
float64 last_calibration_falling_edge

# flag to indicate if this actuator is enabled or not.
# An actuator can only be commanded when it is enabled.
bool is_enabled

# indicates if the motor is halted. A motor can be halted because of a voltage or communication problem
bool halted

# the last current/effort command that was requested
float64 last_commanded_current
float64 last_commanded_effort

# the last current/effort command that was executed by the actuator
float64 last_executed_current
float64 last_executed_effort

# the last current/effort that was measured by the actuator
float64 last_measured_current
float64 last_measured_effort

# the motor voltate
float64 motor_voltage

# the number of detected encoder problems
int32 num_encoder_errors

4.2 pr2_mechanism_msgs/ControllerStatistics

消息文件：pr2_mechanism_msgs/ControllerStatistics.msg

# This message contains the state of one realtime controller
# that was spawned in pr2_mechanism_control

# the name of the controller
string name

# the time at which these controller statistics were measured
time timestamp

# bool that indicates if the controller is currently
# in a running or a stopped state
bool running

# the maximum time the update loop of the controller ever needed to complete
duration max_time

# the average time the update loop of the controller needs to complete.
# the average is computed in a sliding time window.
duration mean_time

# the variance on the time the update loop of the controller needs to complete.
# the variance applies to a sliding time window.
duration variance_time

# the number of times this controller broke the realtime loop
int32 num_control_loop_overruns

# the timestamp of the last time this controller broke the realtime loop
time time_last_control_loop_overrun

4.3 pr2_mechanism_msgs/JointStatistics

消息文件：pr2_mechanism_msgs/JointStatistics.msg

# This message contains the state of one joint of the pr2 robot.
# This message is specificly designed for the pr2 robot.
# A generic joint state message can be found in sensor_msgs::JointState

# the name of the joint
string name

# the time at which these joint statistics were measured
time timestamp

# the position of the joint in radians
float64 position

# the velocity of the joint in radians per second
float64 velocity

# the measured joint effort
float64 measured_effort

# the effort that was commanded to the joint.
# the actual applied effort might be different
# because the safety code can limit the effort
# a joint can apply
float64 commanded_effort

# a flag indicating if the joint is calibrated or not
bool is_calibrated

# a flag inidcating if the joint violated one of its position/velocity/effort limits
# in the last publish cycle
bool violated_limits

# the total distance travelled by the joint, measured in radians.
float64 odometer

# the lowest position reached by the joint in the last publish cycle
float64 min_position

# the highest position reached by the joint in the last publish cycle
float64 max_position

# the maximum absolute velocity reached by the joint in the last publish cycle
float64 max_abs_velocity

# the maximum absolute effort applied by the joint in the last publish cycle
float64 max_abs_effort

4.4 pr2_mechanism_msgs/MechanismStatistics

消息文件：pr2_mechanism_msgs/MechanismStatistics.msg

# This message describes the state of the pr2 mechanism. It contains the state of
# each actuator, each joint, and each controller that is spawned in pr2_mechanism_control.

Header header
ActuatorStatistics[] actuator_statistics
JointStatistics[] joint_statistics
ControllerStatistics[] controller_statistics

五、ROS Service Types

5.1 pr2_mechanism_msgs/ListControllerTypes

服务文件：pr2_mechanism_msgs/ListControllerTypes.srv

# The ListControllers service returns a list of controller types that are known
# to pr2_mechanism_control.
string[] types

5.2 pr2_mechanism_msgs/ListControllers

服务文件：pr2_mechanism_msgs/ListControllers.srv

# The ListControllers service returns a list of controller names that are spawned
# inside pr2_mechanism_control, and their corresponding stats. The state is either
# running or stopped.
string[] controllers
string[] state

5.3 pr2_mechanism_msgs/LoadController

服务文件：pr2_mechanism_msgs/LoadController.srv

# The LoadController service allows you to load a single controller
# inside pr2_controller_manager

# To load a controller, specify the "name" of the controller.
# The return value "ok" indicates if the controller was successfully
# constructed and initialized or not.

string name
bool ok

5.4 pr2_mechanism_msgs/ReloadControllerLibraries

服务文件：pr2_mechanism_msgs/ReloadControllerLibraries.srv

# The ReloadControllerLibraries service will reload all controllers that are available in
# the system as plugins

# Reloading libraries only works if there are no controllers loaded. If there
# are still some controllers loaded, the reloading will fail.
# If this bool is set to true, all loaded controllers will get
# killed automatically, and the reloading can succeed.
bool force_kill
---
bool ok

5.5 pr2_mechanism_msgs/SwitchController

pr2_mechanism_msgs/SwitchController.srv

# The SwitchController service allows you stop a number of controllers
# and start a number of controllers, all in one single timestep of the
# pr2_mechanism_control control loop.

# To switch controllers, specify
#  * the list of controller names to start,
#  * the list of controller names to stop, and
#  * the strictness (BEST_EFFORT or STRICT)
#    * STRICT means that switching will fail if anything goes wrong (an invalid
#      controller name, a controller that failed to start, etc. )
#    * BEST_EFFORT means that even when something goes wrong with on controller,
#      the service will still try to start/stop the remaining controllers

# The return value "ok" indicates if the controllers were switched
# successfully or not. The meaning of success depends on the
# specified strictness.

string[] start_controllers
string[] stop_controllers
int32 strictness
int32 BEST_EFFORT=1
int32 STRICT=2
---
bool ok

5.6 pr2_mechanism_msgs/UnloadController

pr2_mechanism_msgs/UnloadController.srv

# The UnloadController service allows you to unload a single controller
# that is loaded in pr2_controller_manager.

# To unload a controller, specify the "name" of the controller.
# The return value "ok" indicates if the controller was unloaded or not.
# There are three cases when unloadinng a controller will fail:
#  * No controller with the specified name exists
#  * The controller is still running
#  * Another controller depends on the specified controller

string name
---
bool ok

六、ROS Action Types

6.1 pr2_mechanism_msgs/SwitchController

消息文件：pr2_mechanism_msgs/SwitchController.action

string[] start_controllers
string[] stop_controllers
---
---

ROS-Control专题：PR2的六个概念【5】相关推荐

ROS-Control专题：PR2的六个概念【4】
一. 提要 ROS-control是ROS的重要概念,而 ROS-control是通过PR2开发而产生的,因此,实质上,吃透PR2实质就是吃透了ROS-control: ROS-control的基础 ...
ROS-Control专题：PR2的六个概念【3】
参考文: pr2_mechanism - ROS Wiki pr2_controller_interface - ROS Wiki 一. 提要 ROS-control是ROS的重要概念,而 ROS- ...
ROS-Control专题：PR2的六个概念【6】
一. 摘要要学习好ROS-control,先学好PR2.ROS-control的基础是pr2,PR2(Personal Robot 2,简称人形机器人2代)是Willow Garage公司设计的机器 ...
ROS-Control专题：PR2的六个概念【01】
参考文: pr2_mechanism - ROS Wiki pr2_controller_interface - ROS Wiki 一. 摘要要学习好ROS-control,先学好PR2.ROS-c ...
ROS-Control专题：PR2的六个概念【2】
参考文: pr2_mechanism - ROS Wiki pr2_controller_interface - ROS Wiki 一. 摘要 ROS-control的基础是pr2,PR2(Perso ...
20189221 2018-2019-2 《密码与安全新技术专题》第六周作业
20189221 2018-2019-2 <密码与安全新技术专题>第六周作业课程:<密码与安全新技术专题> 班级: 201892 姓名: 郭开世学号:20189221 上课 ...
2018-2019-2 20189206 《密码与安全新技术专题》第六次作业
学号 2018-2019-2 <密码与安全新技术专题>第六次作业课程:<密码与安全新技术专题> 班级: 1892 姓名: 王子榛学号:20189206 上课教师:王志强上 ...
20189216 2018-2019-2 《密码与安全新技术专题》第六次作业
20189216 2018-2019-2 <密码与安全新技术专题>第六次作业课程:<密码与安全新技术专题> 班级: 1892 姓名: 鲍政李学号:20189216 上课教师 ...
ROS探索总结（十六）（十七）（十八）（十九）——HRMRP机器人的设计构建完整的机器人应用系统重读tf 如何配置机器人的导航功能
ROS探索总结(十六)--HRMRP机器人的设计 1. HRMRP简介 HRMRP(Hybrid Real-time Mobile Robot Platform,混合实时移动机器人平台 ...
ROS与Arduino学习（六）Logging日志
ROS与Arduino学习(六)Logging日志 Tutorial Level:客户端与服务器 Next Tutorial:小案例节点通信本节较为简单告诉大家如何向系统发布日志信息. T ...

ROS-Control专题：PR2的六个概念【5】

一、提要

二、pr2的六个关键

2.1 Pr2的六个关键知识点如下

三、关于pr2_mechanism_msgs

四、ROS Message Types

4.1 pr2_mechanism_msgs/ActuatorStatistics

4.2 pr2_mechanism_msgs/ControllerStatistics

4.3 pr2_mechanism_msgs/JointStatistics

4.4 pr2_mechanism_msgs/MechanismStatistics

五、ROS Service Types

5.1 pr2_mechanism_msgs/ListControllerTypes

5.2 pr2_mechanism_msgs/ListControllers

5.3 pr2_mechanism_msgs/LoadController

5.4 pr2_mechanism_msgs/ReloadControllerLibraries

5.5 pr2_mechanism_msgs/SwitchController

5.6 pr2_mechanism_msgs/UnloadController

六、ROS Action Types

6.1 pr2_mechanism_msgs/SwitchController

ROS-Control专题：PR2的六个概念【5】相关推荐

最新文章

热门文章

ROS-Control专题：PR2的六个概念【5】

一、 提要

二、pr2的六个关键

2.1 Pr2的六个关键知识点如下

三、关于pr2_mechanism_msgs

四、ROS Message Types

4.1 pr2_mechanism_msgs/ActuatorStatistics

4.2 pr2_mechanism_msgs/ControllerStatistics

4.3 pr2_mechanism_msgs/JointStatistics

4.4 pr2_mechanism_msgs/MechanismStatistics

五、ROS Service Types

5.1 pr2_mechanism_msgs/ListControllerTypes

5.2 pr2_mechanism_msgs/ListControllers

5.3 pr2_mechanism_msgs/LoadController

5.4 pr2_mechanism_msgs/ReloadControllerLibraries

5.5 pr2_mechanism_msgs/SwitchController

5.6 pr2_mechanism_msgs/UnloadController

六、ROS Action Types

6.1 pr2_mechanism_msgs/SwitchController

ROS-Control专题：PR2的六个概念【5】相关推荐

最新文章

热门文章

一、提要