8.5 Head Joint

8.5.1 Status Interface

1. Get Head Joint Information

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

• Control method: topic

• Topic name: /head/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 # MOS 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

• Example command:

  ros2 topic echo /head/status

8.5.2 Control Interface

1. Position Mode

• Description: Head joint position control interface. Requires desired position, desired velocity, maximum current. Applicable to Walker Tienkung·Embodied Intelligence.
• Control method: topic
• Topic name: /head/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

2. Force/Position Hybrid Mode

• Description: Head joint force/position hybrid control interface. Requires desired position, velocity, feedforward torque, kp, kd coefficients. Applicable to Walker Tienkung·Embodied Intelligence.
• Control method: topic
• Topic name: /head/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

3. Velocity Mode

• Description: Joint velocity control interface. Requires desired velocity, maximum current. Applicable to Walker Tienkung·Embodied Intelligence.
• Control method: topic
• Topic name: /head/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. Head Joint Zero Calibration

• Description: Head joint zero calibration interface. Applicable to Walker Tienkung·Embodied Intelligence.
• Control method: topic
• Topic name: /head/cmd_set_zero
• Data definition location: std_msgs::msg::String
• Data format:

  Send joint id as string to perform zero calibration;
  Head joint ids: 1, 2, 3;