一.urdf文件

Unified Robot Description File，ROS中的机器人描述文件。

主要包含以下节点：

1、sensor/proposals
Describes a sensor, such as a camera, ray sensor,etc.
描述了一个传感器，如相机、光线传感器等
2、link
Describes the kinematic and dynamic properties of a link.
描述一个链接的动态和动态属性。
3、transmission
Transmissions link actuators to joints and represents their mechanical coupling
变速器将执行器连接到接头并表示它们的机械耦合
4、joint
Describes the kinematic and dynamic properties of a joint.
介绍了关节的运动学和动力学特性。
5、gazebo
Describes simulation properties, such as damping, friction, etc
描述仿真属性，如阻尼、摩擦等
6、sensor
Describes a sensor, such as a camera, ray sensor, etc
描述了一个传感器，如相机、光线传感器等
7、model_state
Describes the state of a model at a certain time
在一定时间内描述模型的状态
8、model
Describes the kinematic and dynamic properties of a robot structure.
描述了机器人结构的运动学和动力学特性