ROS package for ZLAC8015D dual-channel servo driver

1 Installation

$ cd catkin_ws/src 

$ git clone https://github.com/Alpaca-zip/zlac8015d_ros.git

$ cd .. && catkin_make

2 Usage

Run motor_driver_node

$ roslaunch zlac8015d_ros motor_driver_node.launch

Parameters

• port: Name of the zlac8015d port. Default is dev/ttyUSB0.
• control_mode: 1 is relative position control mode, 3 is speed rpm control mode. Default is 3.
• debug: If true, odometry information is displayed. Default is false.
• twist_cmd_vel_topic: Topic name for Twist-type messages. Default is /zlac8015d/twist/cmd_vel.
• cmd_vel_topic: Topic name for cmd_vel[m/s] messages. Default is /zlac8015d/vel/cmd_vel.
• cmd_rpm_topic: Topic name for cmd_rpm messages. Default is /zlac8015d/vel/cmd_rpm.
• cmd_deg_topic: Topic name for cmd_deg[°] messages. Default is /zlac8015d/pos/cmd_deg.
• cmd_dist_topic: Topic name for cmd_dist[m] messages. Default is /zlac8015d/pos/cmd_dist.
• publish_TF: If true, TF is published. Default is true.
• TF_header_frame: Name of the TF header frame. Default is odom.
• TF_child_frame: Name of the TF child frame. Default is base_link.
• publish_odom: If true, /odom is published. Default is true.
• odom_header_frame: Name of the odometry header frame. Default is odom.
• odom_child_frame: Name of the odometry child frame. Default is base_link.
• left_wheel_radius: Left wheel radius. Default is 0.1015[m].
• right_wheel_radius: Right wheel radius. Default is 0.1015[m].
• computation_left_wheel_radius: Radius of left wheel used for odometry computation. Default is 0.1015[m].
• computation_right_wheel_radius: Radius of right wheel used for odometry computation. Default is 0.1015[m].
• cpr: CPR(Counts Per Revolution). Default is 16385.
• wheels_base_width: Distance between tires. Default is 0.5668[m].
• callback_timeout: Motor automatically stops if no topics are received for a certain period of time. Default is 0.5[s].
• set_accel_time_left: Acceleration time for left tire. Default is 200[ms].
• set_accel_time_right: Acceleration time for right tire. Default is 200[ms].
• set_decel_time_left: Deceleration time for left tire. Default is 200[ms].
• set_decel_time_right: Deceleration time for right tire. Default is 200[ms].
• max_left_rpm: Maximum rpm of left tire. Default is 150.
• max_right_rpm: Maximum rpm of right tire. Default is 150.
• deadband_rpm: Width of rpm to be regarded as 0. If 3, then -3 to 3 is considered rpm 0. Default is 3.

Topics

This node publishes the following topics.

• /wheels_rpm: The speed in RPM of each tire as [left, right].
• /odom: Odometry data for the robot. More detail

This node subscribes to the following topics.

• /zlac8015d/twist/cmd_vel: Send command as linear velocity and angular velocity in speed rpm control. More detail
• /zlac8015d/vel/cmd_vel: Send command as velocity in speed rpm control, e.g. [0.6, 0.5] 0.6[m/s] of left tire, 0.5[m/s] of right tire.
• /zlac8015d/vel/cmd_rpm: Send command as rpm in speed rpm control, e.g. [100, 50] 100 rpm of left wtire, 50 rpm of right tire.
• /zlac8015d/pos/deg_cmd: Send command as angle degree in position control, e.g. [90,70] 90 [deg] of left tire, 70 [deg] of right tire.
• /zlac8015d/pos/dist_cmd: Send command as desired travelling distance in position control, e.g. [1.0, 1.0] for 1[m] travelling distance of each tire.
• /estop: Send command as emergency stop signal, e.g. true for emergency stop is activated.

Emergency stop Feature

The motor is locked when you publish a true message on the /estop topic.

This feature is not recommended. Emergency stop should be controlled by hardware.