roboglia.base.Joint

class Joint(name='JOINT', device=None, pos_read=None, pos_write=None, activate=None, inverse=False, offset=0.0, minim=None, maxim=None, auto=True, **kwargs)[source]

Bases: object

A Joint is a convenient class to represent a positional device.

A Joint class provides an abstract access to a device providing:

  • access to arbitrary registers in device to retrieve / set the position

  • possibility to invert coordinates

  • possibility to add an offset so that the 0 of the joint is different from the 0 of the device

  • include max and min range in joint coordinates to reflect physical limitation of the joint

Parameters

  • name (str) – The name of the joint

  • device (BaseDevice or subclass) – The device object connected to the joint

  • pos_read (str) – The register name used to retrieve current position

  • pos_write (str) – The register name used to write desired position

  • activate (str or None) – The register name used to control device activation. Optional.

  • inverse (bool) – Indicates inverse coordinate system versus the device; default False

  • offset (float) – Offset of the joint from device’s 0; default 0.0

  • minim (float or None) – Introduces a minimum limit for the joint value; ignored if None which is also the default

  • maxim (float or None) – Introduces a maximum limit for the joint value; ignored if None which is also the default

  • auto (bool) – The joint should activate automatically when the robot starts; defaults to True

__init__(name='JOINT', device=None, pos_read=None, pos_write=None, activate=None, inverse=False, offset=0.0, minim=None, maxim=None, auto=True, **kwargs)[source]

Initialize self. See help(type(self)) for accurate signature.

property name

(read-only) Joint’s name.

property device

(read-only) The device used by joint.

property position_read_register

(read-only) The register for current position.

property position_write_register

(read-only) The register for desired position.

property activate_register

(read-only) The register for activation control.

property active

(read-write) Accessor for activating the joint. If the activation registry was not specified (None) the method will return True (assumes the joints are active by default if not controllable.

The setter will log a warning if you try to assign a value to this property if there is no register assigned to it.

Returns

Value of the activate register or True if no register was specified when the joint was created.

Return type

bool

property auto_activate

Indicates if the joint should automatically be activated when the robot starts.

property inverse

(read-only) Joint uses inverse coordinates versus the device.

property offset

(read-only) The offset between joint coords and device coords.

property range

(read-only) Tuple (min, max) of joint limits.

Returns

A tuple with the min and max limits for the joints. None indicates that the joint does not have a particular limit set.

Return type

(min, max)

property position

Getter uses the read register and applies inverse and offset transformations, setter clips to (min, max) limit if set, applies offset and inverse and writes to the write register.

property desired_position

(read-only) Retrieves the desired position from the write register.

property value

Generic accessor / setter that uses tuples to interact with the joint. For position only joints only position is set.

property desired

Generic accessor for desired joint values. Always a tuple. For position only joints only position attribute is used.

__repr__()[source]

Return repr(self).