BB.Command.MoveTo (bb v0.15.2)

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Standard command handler for moving end-effectors to target positions.

This command uses inverse kinematics to compute joint angles and sends position commands to all actuators controlling the affected joints.

Supports both single-target and multi-target modes for coordinated motion.

Goal Parameters

Single Target Mode

Required:

  • target - Target position as BB.Vec3.t() in metres
  • target_link - Name of the link to move (end-effector)
  • solver - Module implementing BB.IK.Solver behaviour

Multi-Target Mode

Required:

  • targets - Map of link names to target positions: %{link: BB.Vec3.t()}
  • solver - Module implementing BB.IK.Solver behaviour

Optional (both modes)

  • max_iterations - Maximum solver iterations (default: 50)
  • tolerance - Convergence tolerance in metres (default: 1.0e-4)
  • respect_limits - Whether to clamp to joint limits (default: true)
  • delivery - Actuator command delivery: :pubsub (default), :direct, or :sync

Usage

Single Target

alias BB.Vec3

{:ok, cmd} = MyRobot.move_to(%{
  target: Vec3.new(0.3, 0.2, 0.1),
  target_link: :gripper,
  solver: BB.IK.FABRIK
})
{:ok, meta} = BB.Command.await(cmd)

Multiple Targets (for gait, coordinated motion)

{:ok, cmd} = MyRobot.move_to(%{
  targets: %{
    left_foot: Vec3.new(0.1, 0.0, 0.0),
    right_foot: Vec3.new(-0.1, 0.0, 0.0)
  },
  solver: BB.IK.FABRIK
})
{:ok, results} = BB.Command.await(cmd)

Return Value

Single Target

On success, returns metadata from the IK solver:

%{
  iterations: 12,
  residual: 0.00003,
  reached: true,
  reason: :converged
}

Multiple Targets

On success, returns a map of link → result:

%{
  left_foot: {:ok, %{joint1: 0.5}, %{iterations: 10, ...}},
  right_foot: {:ok, %{joint2: 0.3}, %{iterations: 8, ...}}
}