Multi rate processing device for rendering haptic feedback
A haptic interface unit may include an application in the operating system of a device in communication with a driver layer. A plurality of sensors and actuators may be in communication with the driver layer. The driver layer analyzes information from the sensors to generate an output signal based on an interaction model stored in the driver layer. The application updates the interaction model in the driver layer.
1. A haptic interface unit including:
an application operating in a device and an embedded tactile processing unit;
wherein the application includes a global interaction model,
wherein the embedded tactile processing unit is in communication with the application,
wherein the embedded tactile processing unit includes a local interaction model and is configured to produce a haptic output signal to an actuator based on the local interaction model and sensor data input from a plurality of sensor, that corresponds to an appendage of a user disposed on a surface of the device,
wherein the embedded tactile processing unit includes a hardware-timed circuit;
wherein the application updates the local interaction model on the embedded tactile processing unit based on the global interaction model and timing that is asynchronous with the production of the haptic output signal to the actuator.
2. The haptic interface of claim 1 , wherein the plurality of sensors sense a position of the appendage of the user on the surface.
3. The haptic interface of claim 1 , wherein the plurality of sensors sense a pressure applied to the surface by the user.
4. The haptic interface of claim 1 , wherein the embedded tactile processing unit is a hardware implementation that contains both a dedicated soft computing core and the hardware-timed circuit.
5. A method of operating a haptic interface comprising a plurality of sensors, a plurality of actuators, an application, a tactile processing unit, the method comprising the steps of:
reading sensor information corresponding to an appendage of a user on a surface from at least one of the plurality of sensors;
transmitting the sensor information to the tactile processing unit;
processing the sensor information with hardware-timed circuitry in the tactile processing unit to determine a haptic output signal based on a local interaction model stored in the tactile processing unit;
transmitting the haptic output signal from the tactile processing unit to the actuator in accordance with the hardware-timed circuitry of the tactile processing unit;
determining when an input timer of the tactile processing unit has expired in accordance with the hardware-timed circuitry of the tactile processing unit;
reading more sensor information corresponding to the appendage of the user on the surface from at least one of the plurality of sensors when the input timer is not expired;
transmitting the sensor information from the tactile processing unity to the application when the input timer is expired in accordance with the hardware-timed circuitry of the tactile processing unit;
updating a global interaction model in the application based on the sensor information received from the tactile processing unit; and
asynchronously updating the local interaction model based on the global interaction model asynchronously received by the tactile processing unit without interfering with the tactile processing unit processing sensor information.
6. The method of claim 5 , wherein the sensor information includes a position the appendage of the user on the surface.
7. The method of claim 5 , wherein the sensor information includes a pressure of the appendage of the user on the surface.
8. The method of claim 5 , wherein a rate of asynchronously updating the local interaction model is less than 1 kHz.
9. The method of claim 5 , wherein a rate of transmitting the haptic output signal is greater than 20 kHz.