Control of limb device
The invention refers to the area of control of a limb device in the form of an artificial limb for a human or a robot limb. In particular, the invention is related to a control unit for electrically controlling an electrically controllable limb device, the limb device comprising a plurality of actuators, the control unit comprising a first interface for connecting the control unit to the limb device, the control unit comprising a second interface for connecting the control unit to a data gathering device comprising one or more sensing devices, the control unit comprising a processing unit which is arranged for controlling the limb device at least based on data gathered by the data gathering device, wherein the control unit is arranged for outputting one single control action step to the actuators of the limb device calculated by the processing unit based on a first data or data combination received from the data gathering device, and the control unit is arranged for outputting a plurality of control action steps to the actuators of the limb device calculated by the processing unit based on a second data or data combination received from the data gathering device, the second data or data combination being different from the first data or data combination, the plurality of control action steps inducing a more complex automatic movement of the limb device that the one single control action step. The invention further refers to a system comprising such a control unit, a method for controlling an electrically controllable limb device and a computer program.
1. A system for controlling a hand prosthesis comprising:
electromyography (EMG) sensors configured to provide EMG signals from a user's muscles;
a three dimensional (3D) scanning device configured to generate 3D data including depth information of a target viewed by the 3D-scanning device; and
a control unit configured to receive signals from the EMG sensors and the 3D-scanning device, the control unit including:
a myoelectric control module which processes recorded EMG signals and detects activity of the user's muscles,
a controller receiving information about muscle activity from the myoelectric control module which drive state transitions within the controller to implement control logic,
a computer imaging module configured to receive 3D data from the 3D-scanning device and reconstruct a 3D geometrical model of a scene which includes an object that is the target for grasping, and
a hand control module configured to receive information from the computer imaging module and information about hand prosthesis orientation and generate a grasp type and an aperture size appropriate to grasp the object, the hand control module configured to send commands to the hand prosthesis to implement a desired strategy; and
a feedback unit configured to receive information from the computer imaging module and providing feedback to the user.
2. The system for controlling a hand prosthesis according to claim 1 , further comprising an inertial measurement unit attachable to the hand prosthesis which generates 3D position and orientation information of the prosthesis, the control unit further configured to receive the 3D position and orientation information of the prosthesis.
3. The system for controlling a hand prosthesis according to claim 1 , wherein the EMG sensors are configured such that EMG signals are taken from finger flexor and extensor muscle groups of a user.
4. The system for controlling a hand prosthesis according to claim 1 , further comprising an artificial limb to which the hand prosthesis is attached, wherein the EMG sensors are configured to obtain EMG signals from functional muscles around a shoulder of the user.
5. The system for controlling a hand prosthesis according to claim 1 , wherein the feedback unit includes a visual output device outputting visual data showing positions of joints in the hand prosthesis.
6. The system for controlling a hand prosthesis according to claim 1 , wherein the computer imaging module is also configured to receive sensor data from the hand prosthesis in the form of position and force data and use this data to augment the visual feedback to the user.
7. The system for controlling a hand prosthesis according to claim 1 , further comprising a stereo vision device configured as Augmented Reality (AR) glasses wearable by a user and controlled by the computer imaging module to display a 3D picture of a scene in front of the user.
8. The system for controlling a hand prosthesis according to claim 7 , wherein the computer vision module is configured to output a marking signal in a video stream based upon an automatic selection by the control unit of an object which is to be grasped, the marking signal marking the selected object in the 3D picture of the scene in front of the user.
9. The system for controlling a hand prosthesis according to claim 1 , wherein processing in the control unit is organized in a sequential manner and the modules are activated (triggered) by a finite state machine.
10. The system for controlling a hand prosthesis according to claim 1 , wherein the 3D-scanning device is selected from the group consisting of a stereovision camera device, a laser scanning device, a radar device, and a white-light scanning device.