8.6 Waist Joint

8.6.1 Status Interface

1. Get Waist Joint Information

• Description: Get waist joint status information including current position, velocity, current and temperature. Applicable to Walker Tienkung·Voice & Vision and Walker Tienkung·Embodied Intelligence.

• Control method: topic

• Topic name: /waist/status

• Data definition location: bodyctrl_msgs::msg::MotorStatusMsg.msg

• Data format:

  std_msgs/Header header
  MotorStatus[] status
  
  MotorStatus definition:
  uint16 name      # MotorName
  float32 pos      # rad
  float32 speed    # rad
  float32 current  # A
  float32 temperature
  uint32 error

  Error field definitions:

  error = 33072,	Device offline
  error = 33073,	Joint position out of range
  error = 1,	Joint motor overtemp
  error = 2,	Overcurrent
  error = 3,	Low voltage
  error = 4,	Joint MOS overtemp
  error = 5,	Locked rotor
  error = 6,	Overvoltage
  error = 7,	Phase missing
  error = 8,	Encoder error

8.6.2 Control Interface

1. Position Mode

• Description: Joint position control interface. Requires desired position, velocity, maximum current. Applicable to Walker Tienkung·Voice & Vision and Walker Tienkung·Embodied Intelligence.

• Control method: topic

• Topic name: /waist/cmd_pos

• Data definition location: bodyctrl_msgs::msg::CmdSetMotorPosition.msg

• Data format:

  std_msgs/Header header
  SetMotorPosition[] cmds
  
  # SetMotorPosition.msg 
  uint16 name  # MotorName
  float32 pos  # rad
  float32 spd  # rad/s
  float32 cur  # A

• Example commands:

  ros2 topic pub /waist/cmd_pos bodyctrl_msgs/msg/CmdSetMotorPosition "{header: {stamp: {sec: 0, nanosec: 0 }, frame_id: ''},cmds: [{name: 31, pos: -0.3, spd: 0.2, cur: 8.0 }]}"
  ros2 topic pub /waist/cmd_pos bodyctrl_msgs/msg/CmdSetMotorPosition "{header: {stamp: {sec: 0, nanosec: 0 }, frame_id: ''},cmds: [{name: 31, pos: 0.0, spd: 0.2, cur: 8.0 }]}"
  # When using ros2 topic pub command, header can be omitted:
  ros2 topic pub /waist/cmd_pos bodyctrl_msgs/msg/CmdSetMotorPosition "{cmds: [{name: 31, pos: -0.3, spd: 0.2, cur: 8.0 }]}"
  ros2 topic pub /waist/cmd_pos bodyctrl_msgs/msg/CmdSetMotorPosition "{cmds: [{name: 31, pos: 0.0, spd: 0.2, cur: 8.0 }]}"

2. Force/Position Hybrid Mode

• Description: Joint force/position hybrid control interface. Requires desired position, velocity, feedforward torque, kp, kd coefficients. Applicable to Walker Tienkung·Voice & Vision and Walker Tienkung·Embodied Intelligence.

• Control method: topic

• Topic name: /waist/cmd_ctrl

• Data definition location: bodyctrl_msgs::msg::CmdMotorCtrl.msg

• Data format:

  std_msgs/Header header
  MotorCtrl[] cmds
  
  # MotorCtrl.msg
  uint16 name
  float32 kp
  float32 kd
  float32 pos
  float32 spd
  float32 tor

• Example commands:

  ros2 topic pub /waist/cmd_ctrl bodyctrl_msgs/msg/CmdMotorCtrl "{cmds: [{name: 31,kp: 30.0,kd: 10.0,pos: -0.5,spd: 0.0,tor: 0.0}]}"
  ros2 topic pub /waist/cmd_ctrl bodyctrl_msgs/msg/CmdMotorCtrl "{cmds: [{name: 31,kp: 30.0,kd: 10.0,pos: 0.0,spd: 0.0,tor: 0.0}]}"

3. Velocity Mode

• Description: Joint velocity control interface. Requires desired velocity, maximum current. Applicable to Walker Tienkung·Voice & Vision and Walker Tienkung·Embodied Intelligence.
• Control method: topic
• Topic name: /waist/cmd_vel
• Data definition location: bodyctrl_msgs::msg::CmdSetMotorSpeed.msg
• Data format:

  std_msgs/Header header
  SetMotorSpeed[] cmds
  
  # SetMotorSpeed.msg
  uint16 name # MotorName 
  float32 spd # rad/s
  float32 cur # A

4. Waist Joint Zero Calibration

• Description: Waist joint zero calibration interface. When called, the current motor position is set as zero. Remote control "D" zero will move waist motor to this position. Usually used with calibration tools; use with caution without tools. Applicable to Walker Tienkung·Voice & Vision and Walker Tienkung·Embodied Intelligence.
• Control method: topic
• Topic name: /waist/cmd_set_zero
• Data definition location: std_msgs::msg::String
• Data format:

  Send joint id as string to perform zero calibration;
  Waist joint id: 31