Overview

MiRo's Kinematic Chain is described on the Geometry page. A library is provided for manipulating a model of this kinematic chain.

Instantiation

To instantiate a parametrised kinematic chain model fitted to the MiRo robot, use the kc_interf module, which acts as a MiRo-specific interface to the kc library.

The instantiated model is as specified in MiRo's Kinematic Chain. It has the degrees of freedom (DOFs): POSE, TILT, LIFT, YAW, and PITCH. It has the frames: WORLD, FOOT, BODY, NECK, GIMBAL, HEAD.

Example

Here, we create a model of MiRo's kinematic chain in variable kc.

import miro2 as miro ... kc = miro.lib.kc_interf.kc_miro()

Constants

Frame constants

Frames are specified with one of the frame constants.

LINK_WORLD: The world frame.
LINK_FOOT: MiRo's footprint (roughly, the projection of BODY onto the z=0 plane in WORLD). Related to WORLD by a translation in the plane, specified by POSE.
LINK_BODY: MiRo's body.
LINK_NECK: Internal frame.
LINK_GIMBAL: Internal frame.
LINK_HEAD: MiRo's head.

Example

Here, we transform a position from WORLD into HEAD using a kc model, specifying the input and output frames using frame constants.

import miro2 as miro ... xyz_HEAD = kc.changeFrameAbs(miro.constants.LINK_WORLD, miro.constants.LINK_HEAD, xyz_WORLD)

Functions

kc.zeroPose(): Reset the DOF POSE [x, y, theta] to all-zero.
kc.getPose(): Return the DOF POSE as an array [x, y, theta].
At R210921 and earlier, this function returns the data as a tuple ([x, y], theta).
kc.setPose(pose): Set the DOF POSE as an array pose = [x, y, theta].
kc.getConfig(): Get the remaining DOFs as an array [TILT, LIFT, YAW, PITCH].
kc.setConfig(config): Set the remaining DOFs as an array config = [TILT, LIFT, YAW, PITCH]. No checking is performed, so the model can be configured in a way that is not physically realisable. TILT should always be set to miro.constants.TILT_RAD_CALIB.
kc.getState(): Get pose and config as one list [pose, config].
kc.getStateInit(): Return result of getState() called immediately after instantiation, for later reference.
kc.getPoseInit(), getConfigInit(): Return just pose or config as for getStateInit().
kc.changeFrameAbs(inFrame, outFrame, pos): Transform the passed position pos from the frame inFrame to the frame outFrame. Both frame arguments should be frame constants.
kc.changeFrameRel(inFrame, outFrame, dir): Transform the passed direction dir from the frame inFrame to the frame outFrame. Both frame arguments should be frame constants.

Example

See client_map and example_kc on the Examples page for more in-depth examples of usage.