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

• US 8,712,614 B2
• Filed: 04/29/2011
• Issued: 04/29/2014
• Est. Priority Date: 04/29/2010
• Status: Expired due to Fees

• Current Assignee: Sunrise Medical Us LLC (Sunrise Medical Incorporated)
• Original Assignee: Andrew J. Parker
• Inventors: Parker, Andrew
• Primary Examiner(s): Olszewski, John R
• Assistant Examiner(s): CASS, JEAN PAUL
• Application Number:
  US13/068,053
• Publication Number:
  US 20110270478A1
• Time in Patent Office: 1,096 Days
• Field of Search: None
• 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

An interface for use with a pressure-based wheelchair joystick, which enables highly sensitive calibration of the pressure-based joystick, and allows the user to control the wheelchair.

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) a microcontroller detecting a voltage signal sent from a calibration button located on a wheelchair interface and wherein the voltage signal is sent when a pressure-based wheelchair joystick is in a neutral state;

(b) the microcontroller initiating an idle state for a predetermined period of time upon detection of the voltage signal sent from the calibration button;

(c) the microcontroller pausing for the predetermined period of time, the microcontroller determining whether a calibration button is being pressed by determining if a voltage signal sent from the calibration button is detectable;

(d) the microcontroller detecting a neutral input signal sent from the pressure-based wheelchair joystick when the wheelchair joystick is in a neutral position, wherein the microcontroller stores the neutral input signal as an initial value for each axis of the pressure-based wheelchair joystick

(e) the microcontroller determining a deadband using the detected input signal, wherein the deadband is a range including a minimum value that is defined as the input signal minus 24 milliVolts and a maximum value that is defined as the input signal plus 24 milliVolts;

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

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

(h) the microcontroller determining if the first input signal is outside the neutral range value;

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

(j) the microcontroller transmitting an output signal to a wheelchair, the output signal corresponding to the value of the first input signal;

(k) the microcontroller verifying that the value of the first input signal is within a predetermined fault range;

(l) the microcontroller outputting a signal if the value of the first input signal is outside the fault range; and

(m) the microcontroller deactivating the wheelchair in response to the first input signal being within the predetermined fault range.

2. A processor implemented method as defined in claim 1, wherein step (h) further comprises the step of the microcontroller detecting a second input signal if the value of the first input signal is within the neutral range.

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

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

1. detecting a voltage signal received when a calibration button on the pressure-based wheelchair is pressed, wherein the voltage signal is received when the pressure-based wheelchair joystick is in a neutral position;

2. initiating an idle state for a predetermined period of time;

3. determining whether the voltage signal is still being sent;

4. upon determining that the voltage signal is still being sent, receiving an input signal;

5. determining a deadband using the detected input signal;

6. storing the deadband as a neutral range value and wherein the neutral range includes a minimum value that is defined as the input signal minus 24 milliVolts and a maximum value that is defined as the input signal plus 24 milliVolts;

7. detecting a first input signal, the first input signal having a corresponding value, where the first input signal is received from the pressure-based wheelchair joystick;

8. determining if the first input signal is out of the neutral range value;

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

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

11. verifying that the value of the first input signal is within a predetermined fault range;

12. outputting a signal if the value of the first input signal is outside the fault range; and

13. deactivating the wheelchair in response to a fault signal

(b) a first filter coupled to an input of the microcontroller;

(c) an amplifier coupled to an output of the microcontroller; and

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