Titan

The Titan provides CAN bus DC motor control for up to 4 motors per unit, with closed-loop velocity and position control via the onboard S-Curve algorithm.

Configuration

titan:
  enabled: true
  sensors: ["titan0"]
  titan0:
    can_id: 42
    motor_freq: 15600
    encoder_rate_hz: 20
    motor_update_rate_hz: 50
    limit_switches: false
    m_0:
      encoder_mode: "quadrature"
      dist_per_tick: 0.0006830601
      invert_motor: false
      invert_encoder: false
      invert_rpm: false
    m_1:
      encoder_mode: "quadrature"
      dist_per_tick: 0.0006830601
    m_2:
      encoder_mode: "absolute"
    m_3:
      encoder_mode: "quadrature"
      dist_per_tick: 0.0006830601

Parameters

Parameter	Description
`can_id`	CAN bus ID of the Titan unit
`motor_freq`	PWM frequency in Hz
`encoder_rate_hz`	Encoder topic publish frequency (default `20`)
`motor_update_rate_hz`	Internal motor command rate (default `50`)
`limit_switches`	Enable limit switch inputs (default `false`)
`m_N.encoder_mode`	`"quadrature"` or `"absolute"`
`m_N.dist_per_tick`	Metres per encoder tick — required for quadrature mode
`m_N.invert_motor`	Flip positive direction (default `false`)
`m_N.invert_encoder`	Flip encoder count direction (default `false`)
`m_N.invert_rpm`	Flip RPM sign (default `false`)

note

Use encoder_mode: "absolute" when using a Cypher Max absolute encoder. dist_per_tick has no effect in absolute mode.

Topics

Subscribed

Topic	Type	Description
`/<name>/m_N/cmd`	`std_msgs/Float64`	Motor duty cycle command (−1.0 to 1.0)

Published

Topic	Type	Description	Rate
`/<name>/m_N/encoder`	`std_msgs/Float64`	Encoder distance (quadrature mode)	`encoder_rate_hz`
`/<name>/m_N/rpm`	`std_msgs/Float64`	Motor RPM (quadrature mode)	`encoder_rate_hz`
`/<name>/m_N/angle`	`std_msgs/Float64`	Absolute angle in degrees (absolute mode)	`encoder_rate_hz`
`/<name>/m_N/limit_fwd`	`std_msgs/Bool`	Forward limit switch state	`encoder_rate_hz`
`/<name>/m_N/limit_rev`	`std_msgs/Bool`	Reverse limit switch state	`encoder_rate_hz`

info

Limit switch topics publish only when limit_switches: true.

Service

Service name: /<name>/titan_cmd
Type: studica_control/SetData

Command	Required Fields	Description
`enable`	—	Power on the controller
`disable`	—	Power off; all motors stop
`set_speed`	`n_encoder`, `speed`	Set motor duty cycle (−1.0 to 1.0)
`set_speed_all`	`speed`	Set all 4 motors to the same duty cycle
`stop`	`n_encoder`	Stop one motor
`disable_motor`	`n_encoder`	Cut power to one motor
`set_target_velocity`	`n_encoder`, `speed`	Closed-loop velocity in RPM
`set_target_distance`	`n_encoder`, `int_value`	Closed-loop position in encoder counts
`set_target_angle`	`n_encoder`, `speed`	Drive to target angle in degrees
`set_position_hold`	`n_encoder`, `hold`	Lock motor at current position
`configure_encoder`	`n_encoder`, `dist_per_tick`	Override distance per tick at runtime
`reset_encoder`	`n_encoder`	Zero one encoder
`invert_motor`	`n_encoder`	Flip positive direction at runtime
`get_rpm`	`n_encoder`	Read current RPM
`get_encoder_count`	`n_encoder`	Read raw tick count
`get_encoder_distance`	`n_encoder`	Read odometry distance
`get_firmware_version`	—	Firmware version string

Configuration​

Parameters​

Topics​

Subscribed​

Published​

Service​