rby1_sdk.JointVelocityCommandBuilder#

class JointVelocityCommandBuilder#

Bases: pybind11_object

Joint velocity command builder.

Builds a joint-space velocity command with optional acceleration limits. When a target velocity vector \(v_d\) is set, the command generates a linear ramp from the current velocity \(v_{curr}\) to \(v_d\), considering both acceleration limits and the specified minimum time.

The controller’s objective is to reach the target velocity. If you need the robot to hold the target velocity after reaching it, you must specify a control hold time in the command header.

Examples

>>> import numpy as np, rby1_sdk as rby
>>> # Ramp torso joints to 0.5 rad/s with acceleration limits
>>> cmd = (
...     rby.JointVelocityCommandBuilder()
...     .set_velocity(np.full(6, 0.5))
...     .set_acceleration_limit(np.full(6, 2.0))
...     .set_minimum_time(1.0)
... )
>>> # To maintain the velocity after reaching 0.5 rad/s,
>>> # add a CommandHeader with control_hold_time.
>>> header = rby.CommandHeaderBuilder().set_control_hold_time(5.0)
>>> cmd.set_command_header(header)

__init__(self: rby1_sdk.JointVelocityCommandBuilder) → None#

Methods

`__init__`(self)
`set_acceleration_limit`(self, acceleration_limit)	Set per-joint acceleration limits.
`set_command_header`(self, command_header_builder)	Attach a command header.
`set_minimum_time`(self, minimum_time)	Set the minimum execution time.
`set_velocity`(self, velocity)	Set desired joint velocities.

set_acceleration_limit(self: rby1_sdk.JointVelocityCommandBuilder, acceleration_limit: numpy.ndarray[numpy.float64[m, 1]]) → rby1_sdk.JointVelocityCommandBuilder#

Set per-joint acceleration limits.

Parameters:: acceleration_limit (numpy.ndarray, shape (N,), dtype=float64) – Maximum allowable accelerations [rad/s²]. Length \(N\) must equal the number of joints in the targeted component.
Returns:: Self reference for method chaining.
Return type:: JointVelocityCommandBuilder

Notes

These limits shape the linear ramp profile toward the target velocity.
If not set, URDF defaults are used (see get_robot_model).

set_command_header(self: rby1_sdk.JointVelocityCommandBuilder, command_header_builder: rby1_sdk.CommandHeaderBuilder) → rby1_sdk.JointVelocityCommandBuilder#

Attach a command header.

Parameters:: command_header_builder (CommandHeaderBuilder) – Command header configuration (e.g., control hold time).
Returns:: Self reference for method chaining.
Return type:: JointVelocityCommandBuilder

Notes

Use control_hold_time to maintain the commanded velocity once reached.

set_minimum_time(self: rby1_sdk.JointVelocityCommandBuilder, minimum_time: float) → rby1_sdk.JointVelocityCommandBuilder#

Set the minimum execution time.

Parameters:: minimum_time (float) – Minimum execution time in seconds. Ensures the ramping process to the target velocity is stretched at least over this duration.
Returns:: Self reference for method chaining.
Return type:: JointVelocityCommandBuilder

set_velocity(self: rby1_sdk.JointVelocityCommandBuilder, velocity: numpy.ndarray[numpy.float64[m, 1]]) → rby1_sdk.JointVelocityCommandBuilder#

Set desired joint velocities.

Parameters:: velocity (numpy.ndarray, shape (N,), dtype=float64) – Per-joint target velocities [rad/s]. Length \(N\) must equal the number of joints in the targeted component.
Returns:: Self reference for method chaining.
Return type:: JointVelocityCommandBuilder

Notes

The command ramps linearly from the current velocity to the target velocity.
To hold the target velocity after reaching it, add a command header with a control hold time.