roboglia.base.JointManager

class JointManager(name='JointManager', frequency=100.0, joints=[], group=None, function='mean', p_function=None, v_function=None, ld_function=None, timeout=0.5, **kwargs)

Bases: roboglia.base.thread.BaseLoop

Implements the management of the joints by alowing multiple movement streams to submit position commands to the robot.

The JointManager inherits the constructor paramters from BaseLoop. Please refer to that class for mote details.

In addition the class introduces the following additional paramters:

Parameters

• joints (list of :py:class:roboglia.Base.`Joint` or subclass) – The list of joints that the manager is having under control. Alternatively you can use the parameter group (see below)

• group (set of :py:class:roboglia.Base.`Joint` or subclass) – A group of joints that was defined earlier with a group statement in the robot definition file.

• function (str) – The function used to produce the blended command for the joints. If specific functions for position (p_function), velocity ( v_function) or load (ld_function) are not supplied, then this function is used. Allowed values are ‘mean’, ‘median’, ‘min’, ‘max’.

• p_function (str) – A specific function to be used for aggregating the position values. Allowed values are ‘mean’, ‘median’, ‘min’, ‘max’.

• v_function (str) – A specific function to be used for aggregating the velocity values. Allowed values are ‘mean’, ‘median’, ‘min’, ‘max’.

• ld_function (str) – A specific function to be used for aggregating the load values. Allowed values are ‘mean’, ‘median’, ‘min’, ‘max’.

• timeout (float) – Is a time in seconds an accessor will wait before issuing a timeout when trying to submit data to the manager or the manager preparing the data for the joints.

__init__(name='JointManager', frequency=100.0, joints=[], group=None, function='mean', p_function=None, v_function=None, ld_function=None, timeout=0.5, **kwargs)

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

property p_func

Aggregate function for positions.

property v_func

Aggregate function for positions.

property ld_func

Aggregate function for positions.

submit(stream, commands, adjustments=False)

Used by a stream of commands to notify the Joint Manager they joint commands they want.

Parameters

• stream (BaseThread or subclass) – The stream providing the data. It is used to keep the request separate and be able to merge later.

• commands (dict) –

  A dictionary with the commands requests in the format:

  {joint_name: (values)}
  

  Where values is a tuple with the command for that joint. It is acceptable to send partial commands to a joint, for instance you can send only (100,) meaning position 100 to a JointPVL. Submitting more information to a joint will have no effect, for instance (100, 20, 40) (position, velocity, load) to a Joint will only use the position part of the request.

• adjustments (bool) – Indicates that the values are to be treated as adjustments to the other requests instead of absolute requests. This is convenient for streams that request postion correction like an accelerometer based balance control. Internally the JointManger keeps the commands separate between the absolute and the adjustments ones and calculates separate averages then adjusts the absolute results with the ones from the adjustments to produce the final numbers.

Returns

True if the operation was successful. False if there was an error (most likely the lock was not acquired). Caller needs to review this and decide if they should retry to send data.

Return type

bool

stop_submit(stream, adjustments=False)

Notifies the JointManager that the stream has finished sending data and as a result the data in the JointManager cache should be removed.

Warning

If the stream does not call this method when it finished with a routine the last submission will remain in the cache and will continue to be averaged with the other requests, creating problems. Don’t forget to call this method when your move finishes!

Parameters

• stream (BaseThread or subclass) – The name of the move sending the data

• adjustments (bool) – Indicates the move submitted to the adjustment stream.

Returns

True if the operation was successful. False if there was an error (most likely the lock was not acquired). Caller needs to review this and decide if they should retry to send data. In the case of this method it is advisable to try resending the request, otherwise stale data will stay in the cache.

Return type

bool

start()

Starts the JointManager. Before calling the BaseThread.start() it activates the joints if they indicate they have the auto flag set.

stop()

Stops the JointManager. After calling the BaseThread.stop() it deactivates the joints if they indicate they have the auto flag set.

atomic()

This method implements the periodic task that needs to be executed. It does not need to check paused or stopped as the run method does this already and the subclasses should make sure that the implementation completes quickly and does not raise any exceptions.

property actual_frequency

Returns the actual running frequency that is calculated by statistics.

property error_stat

(error in %, total errors, total items).

Type

Returns the error statistics as a tuple

property errors

Returns the number of errors logged by the statistics.

property frequency

Loop frequency.

inc_errors()

Used by subclasses to increment the number of errors.

inc_processed()

Used by subclasses to increment the number of processed items.

property name

Returns the name of the thread.

pause()

Requests the thread to pause.

property paused

Indicates the thread was paused.

property period

Loop period = 1 / frequency.

property processed

Returns the number of items processed in the current statistics. The items processed depends on the loop and might be different from the number of loops executed. For example the one execution loop might include several communication packets.

resume()

Requests the thread to resume.

property review

Indicates the amount of time in seconds before the thread will review the actual frequency against the target and take action.

run()

Run method of the thread.

property running

Indicates if the thread is running.

setup()

Thread preparation before running. Subclasses should override

property started

Indicates if the thread was started.

property stopped

Indicates if the thread was stopped.

teardown()

Thread cleanup. Subclasses should override.

property warning

Control the warning level for the warning message, the setter is smart: if the value is larger than 2 it will assume it is a percentage and divied it by 100 and ignore if the number is higher than 110. The over 100 is available for testing purposes.