System, method, and computer readable medium for a force-based wheelchair joystick

• US 20110270478A1
• Filed: 04/29/2011
• Published: 11/03/2011
• Est. Priority Date: 04/29/2010
• Status: Active Grant

• Current Assignee: Sunrise Medical Us LLC (Sunrise Medical Incorporated)
• Original Assignee: Andrew J. Parker
• Inventors: Parker, Andrew
• Granted Patent: US 8,712,614 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60L 2200/34 Wheel chairs
• CPC Class Codes: B60L 2270/145 Structure borne vibrations
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables

Abstract

The present invention provides an interface for use with a pressure-based wheelchair joystick. The interface comprises circuitry which enables highly sensitive calibration of the pressure-based joystick, and allows the user to control the wheelchair thereafter. The present invention also provides a protective sleeve for the pressure-based joystick, thereby providing increased durability.

Claims

1. A processor implemented method for using an interface for use with a pressure-based wheelchair joystick, the method comprising the steps of:

(a) detecting a calibration input signal by a microcontroller, the calibration input signal being received from the pressure-based wheelchair joystick;

(b) initiating an idle state for a predetermined period of time;

(c) determining whether the calibration input signal is still being detected at the microcontroller;

(d) continuing to detect the calibration input signal;

(e) determining a deadband using the detected calibration input signal, wherein this step further comprises the steps of;

determining a lower threshold with respect to the detected calibration input signal; and

determining an upper threshold with respect to the detected calibration input signal,

wherein the lower and upper thresholds represent the deadband; and

(f) storing the deadband as a neutral range value.

2. A processor implemented method as defined in claim 1, wherein the lower threshold is determined to be minus 24 mV from the detected calibration input signal, and the upper threshold is determined to be plus 24 mV from the detected calibration input signal.

3. A processor implemented method for using an interface for use with a pressure-based wheelchair joystick, the method comprising the steps of:

(a) detecting a first input signal by a microcontroller, the first input signal having a corresponding value, wherein the first input signal is received from the pressure-based wheelchair joystick;

(b) retrieving a neutral range value from memory;

(c) verifying that the value of the first input signal is outside the neutral range;

(d) verifying that the value of the first input signal is within a fault range; and

(e) transmitting an output signal to a wheelchair, the output signal corresponding to the value of the first input signal.

4. A processor implemented method as defined in claim 3, wherein step (c) further comprises the step of detecting a second input signal if the value of the first input signal is within the neutral range.

5. A processor implemented method as defined in claim 3, wherein step (d) further comprises the step of outputting a fault signal if the value of the first input signal is outside the fault range.

6. A processor implemented method as defined in claim 5, further comprising the step of deactivating the wheelchair in response to the fault signal.

7. A non-transitory computer readable medium containing a computer program product for interfacing a pressure-based joystick with a wheelchair, the computer program product comprising instructions for executing the steps of:

(a) detecting a calibration input signal by a microcontroller, the calibration input signal being received from the pressure-based wheelchair joystick;

(b) initiating an idle state for a predetermined period of time;

(c) determining whether the calibration input signal is still being detected at the microcontroller;

(d) continuing to detect the calibration input signal;

(e) determining a deadband using the detected calibration input signal, wherein this step further comprises the steps of;

determining a lower threshold with respect to the detected calibration input signal; and

determining an upper threshold with respect to the detected calibration input signal,

wherein the lower and upper thresholds represent the deadband; and

(f) storing the deadband as a neutral range value.

8. A non-transitory computer readable medium containing a computer program product as defined in claim 7, wherein the lower threshold is determined to be minus 24 mV from the detected calibration input signal, and the upper threshold is determined to be plus 24 mV from the detected calibration input signal.

9. A non-transitory computer readable medium containing a computer program product for interfacing a pressure-based joystick with a wheelchair, the computer program product comprising instructions for executing the steps of:

(a) detecting a first input signal by a microcontroller, the first input signal having a corresponding value, wherein the first input signal is received from the pressure-based wheelchair joystick;

(b) retrieving a neutral range value from memory;

(c) verifying that the value of the first input signal is outside the neutral range;

(d) verifying that the value of the first input signal is within a fault range; and

(e) transmitting an output signal to a wheelchair, the output signal corresponding to the value of the first input signal.

10. A non-transitory computer readable medium containing a computer program product as defined in claim 9, wherein step (c) further comprises the step of detecting a second input signal if the value of the first input signal is within the neutral range.

11. A non-transitory computer readable medium containing a computer program product as defined in claim 9, wherein step (d) further comprises the step of outputting a fault signal if the value of the first input signal is outside the fault range.

12. A non-transitory computer readable medium containing a computer program product as defined in claim 11, further comprising the step of deactivating the wheelchair in response to the fault signal.

13. An interface for use with a pressure-based wheelchair joystick, the interface comprising:

a microcontroller to implement instructions in response to input signals received from the pressure-based wheelchair joystick, the instructions comprising the steps of;

detecting a calibration input signal received from the pressure-based wheelchair joystick;

initiating an idle state for a predetermined period of time;

determining whether the calibration input signal is still being detected;

continuing to detect the calibration input signal;

determining a deadband using the detected calibration input signal; and

storing the deadband as a neutral range value;

a first filter coupled to an input of the microcontroller;

an amplifier coupled to an output of the microcontroller; and

a voltage divider circuit coupled to an output of the amplifier to feed an output signal back into the microcontroller.

14. An interface for use with a pressure-based wheelchair joystick, the interface comprising:

a microcontroller to implement instructions in response to input signals received from the pressure-based wheelchair joystick, the instructions comprising the steps of;

detecting a first input signal by the microcontroller, the first input signal having a corresponding value, wherein the first input signal is received from the pressure-based wheelchair joystick;

retrieving a neutral range value from memory;

verifying that the value of the first input signal is outside the neutral range;

verifying that the value of the first input signal is within a fault range; and

transmitting an output signal to a wheelchair, the output signal corresponding to the value of the first input signal;

;

a first filter coupled to an input of the microcontroller;

an amplifier coupled to an output of the microcontroller; and

a voltage divider circuit coupled to an output of the amplifier to feed an output signal back into the microcontroller.