Patent Application
20080294300
This invention was not made by an agency of the United States Government nor under contract with an agency of the United States Government.
The present invention relates to a microprocessing device used in conjunction with capacitive elements for sensing a position of an object and producing an output signal as a function of the position. It finds particular application in conjunction with controlling the operation of a motorized wheelchair and will be described with particular reference thereto. It will be appreciated, however, that the invention is also amenable to other like applications.
A Wheelchair enables a disabled person, whose ability to move is restricted, to move about from place to place with an added degree of freedom. Conventional motorized wheelchairs enable a user to move by manipulating a few wheelchair controls. Wheelchair controls are typically hand operated devices. However, wheelchair controls adapted for special needs have been designed for wheelchair users who do not have use of their hands to operate the controls.
Such wheelchair controls adapted for special needs have been addressed, in part, by providing wheelchair control systems that rely on controlled movements of other body parts of a user (e.g., controls operated by a leg, chin, or head). Controls that utilize movement of the head to activate wheelchair controls exist which use reflecting mirrors attached to the head and moveable with the head while others use ultrasonic techniques to bounce sound waves from the head and thus determine its position for controlling the wheelchair. Wheelchair control systems of these types are described in U.S. Pat. Nos. 3,374,845; 3,965,402; 3,993,154; 4,281,734; 4,093,037; and 4,679,644.
U.S. Pat. No. 3,761,736 describes a proximity switch operating on a capacitance principle to detect changes in capacitance occurring when an object comes in close proximity to the switch. Capacitance principles are also employed in the apparatus of U.S. Pat. No. 3,993,154 wherein a low-power signal is carried by a conductor to a thin conductive metal foil located in a back rest portion of a motorized wheelchair. One drawback of sensing circuits used for these types of wheelchair controls is that contact with the body is required. Such contact may take the form of a helmet or mirrors attached to the head or actual physical body contact with a part of a wheelchair.
U.S. Pat. No. 4,767,940 (“the '940 patent”), which is hereby incorporated by reference, discloses a sensing circuit for a wheelchair control that does not require physical contact with the user's body and does not hinder the user's field of vision or mobility. However, the sensing circuit incorporates proportional signals from sensors for controlling both forward/reverse movements and left/right turns of the wheelchair and, furthermore, requires relatively complicated circuitry.
Users of power wheelchairs often times do not have a great amount of control over their head (or other body parts) for controlling the wheelchair. Furthermore, such persons often times have significantly less control over side-to-side movements of the head, which are typically used for turning the wheelchair to the left and right, than front-to-rear movements, which are typically used for moving the wheelchair forward and backward. Consequently, a user may be capable of performing proportional movements to the front and rear for achieving an acceptable level of control over both the speed and direction while moving the wheelchair forward and/or backward. However, it is not uncommon that the same user may not be capable of performing side-to-side proportional movements for achieving an acceptable level of control over both the speed and direction while moving the wheelchair left and/or right. For these reasons, proportional capacitive proximity sensors are desirable for sensing front-to-rear movements, but not side-to-side movements, of a users head.
The present invention provides a new and improved apparatus and method which addresses the above-references problems.
An electronic controller for a motorized device includes a signal generator generating an output signal to the motorized device. A non-proportional proximity sensor communicates with the signal generator. A proportional proximity sensor communicates with the signal generator. The output signal is determined as a function of respective signals communicated from the proximity sensors to the signal generator. A direction and speed of the motorized device is determined as a function of the output signal.
In one aspect, each of the proximity sensors is a capacitive sensor.
In another aspect, an analog-to-digital converter converts the respective signals from each of the proximity sensors from an analog format to a digital format. The digital format of the respective signals is communicated to the signal generator.
In another aspect, a second non-proportional proximity sensor communicates with the signal generator. The output signal is determined as a function of respective signals communicated from each of the proximity sensors to the signal generator. The proximity sensors are formed into an array.
In another aspect, the array is positioned around a movable body part of a user transported by the motorized device.
In another aspect, the body part is a head.
In another aspect, if the body part is within an operating range of the first non-proportional proximity sensor, the signal communicated from the first non-proportional proximity sensor to the signal generator includes one of a left-turn and a right-turn indicator. If the body part is within an operating range of the second non-proportional proximity sensor, the signal communicated from the second non-proportional proximity sensor to the signal generator includes the other of a left-turn and a right-turn indicator. The signal communicated from the proportional proximity sensor indicates a distance of the body part from the proportional proximity sensor. The speed is set as a function of the distance of the body part from the proportional proximity sensor. The direction is set as a function of the left-turn and right-turn indicators.
In another aspect, if the distance of the body part from the proportional proximity sensor is beyond a predetermined limit, the speed is set to zero.
In another aspect, if one of the left-turn and right-turn indicators is included in the signal communicated to the signal generator, the direction is set between 0° and ±90°.
In another embodiment, a method for controlling a motorized device includes generating a first direction signal as a function of a distance of an object relative to a first, non-proportional sensor. A speed signal is generated as a function of a distance of the object relative to a second, proportional sensor. An output signal is generated for controlling the device as a function of the first direction and speed signals.
In the accompanying drawings which are incorporated in and constitute a part of the specification, embodiments of the invention are illustrated, which together with a general description of the invention given above, and the detailed description given below, serve to exemplify the embodiments of this invention.
With reference to
The sensors 30, 32 represent non-proportional side 9 e.g., left and right, respectively) proximity sensors, which act as on/off switches, while the sensor 34 represents a proportional center proximity sensor. The sensor 34 is optionally covered by a pad 42 (e.g., foam pad) and, therefore, is hidden from plain view and illustrated using dashed lines. It is to be understood in this embodiment, the head of the user is positioned within the array of sensors 30, 32, 34 such that the non-proportional side proximity sensors 30, 32 are positioned on the left and right sides, respectively, of the head and the proportional center proximity sensor 34 is positioned behind the head.
The non-proportional proximity sensors 30, 32 are contemplated in one embodiment to have a predetermined operating range (e.g., about ⅜″). More specifically, the sensors 30,32 detect the presence of the body part 24 (e.g., the head) when the body part is within the predetermined operating range (e.g., abut ⅜″ or closer to the sensors 30, 32). The respective sensors 30, 32 turn to an “ON” mode when the presence of the body part is detected; otherwise, the sensors 30, 32 are in an “OFF” mode. In one embodiment, the non-proportional proximity sensors 30, 32 are manufactured by Omron and are identified as part number E2K-F10MC1; however, other non-proportional proximity sensors are also contemplated.
The proportional proximity sensor 34 transits a signal to the control module 22 as a function of a distance between the sensor and the body part 24. In one embodiment, the proportional proximity sensor 34 has a longer range relative to the non-proportional proximity sensors 30, 32. For example, it is contemplated in one embodiment that the proportional proximity sensor 34 has a range of about 2½″. In this case, the sensor 34 crates a signal proportional to a distance of the body part 24 from the sensor 34 over the range of about 2½″. One example of the proportional proximity sensor 34 is embodied in the '940 patent; however, other proportional proximity sensors 34 are also contemplated.
In one embodiment, the signals transmitted from the sensors 30, 32, 34 are in an analog format. An analog-to-digital converter 44 within the control module 22 transforms the analog signals from the sensors 30, 32, 34 to respective signals having digital formats. Other embodiments, in which some or all of the signals transmitted from the sensors 30, 32, 34 to the control module 22 are in a digital format are also contemplated.
The digital signals from the converter 44 or from the sensors 30, 32, 34 are transmitted to a controller 50 (e.g., an electronic microprocessor or microcontroller). The controller 50 generates an output signal as a function of the signals received. In this sense, the controller 50 is a signal generator. More specifically, the control 50 determined a speed as a function of the signal received from the proportional proximity sensor 34 and directional information as a function of the signal received from the non-proportional sensors 30, 32.
If the signal transmitted from the left non-proportional proximity sensor 30 indicates the body part 24 is within the predetermined operating range of the sensor 30 (e.g., the body part is within ⅜″ of the proximity sensor 30), a directional component of the output signal includes a left turn signal. If the signal transmitted from the right non-proportional proximity sensor 32 indicates the body part 24 is within the predetermined operating range of the sensor 32 (e.g., the body part is within ⅜″ of the proximity sensors 32), a directional component of the output signal includes a right turn signal. If neither the left proportional sensors 30 nor the right non-proportional sensor 32 indicates the body part 24 is within the predetermined operating ranges of the respective sensors 30, 32, a directional component of the output signal includes a no-turn (e.g., straight) signal. If both the left and right non-proportional sensors 30, 32 indicate the body part 24 is within the predetermined operating ranges of the respective sensors 30, 32, an error code is generated within the adapter 36 and a speed component of the output signal includes a command to stop the device 10. Otherwise, the speed component of the output signal includes a signal determined as a function of a distance between the body part 24 and the proportional proximity sensor 34.
If the directional component of the output signal includes one of the left and right turn signals, the control module 22 causes the device to veer (e.g., turn at about 45°) towards the respective direction at a speed determined as a function of the distance of the body part from the proportional proximity sensor 34. Importantly, because the left and right proximity sensors 30, 32 are non-proportional, the direction of the device 10 is merely set as “LEFT,” “RIGHT,” or “STRAIGHT.” In other words, the direction of the device 10 is not set as a function of the distance between the body part and the left and right proximity sensors 30, 32 and, instead, veers left if the body part is within the predetermined operating range of the left sensor 30 and veers right if the body part is within the predetermined operating range of the right sensor 32. Although it is contemplated the angle of the veer is about 45° in either the left or right direction, other angles (e.g., in the range of 0°±180°) are also contemplated.
It is to be understood that the sensor module 20 optionally includes a switch 48 that may be 9 operated by the user's body part for changing the drive direction of the device 20 between forward and reverse modes. More specifically, if the device 10 is in a first mode (e.g., the forward mode) and the user desired to switch to a second mode (e.g., the reverse mode), the user may move his/her body part to activate the switch to change modes. It is to be understood the user may switch between modes as desired. In one embodiment, the switch is contemplated to be a single-pole double-through switch; however, a toggle switch, or any other type of switch, is also contemplated.
It is also contemplated in other embodiments that the user may change the direction of the device 20 by moving his/her body part 24 in a predetermined pattern relative to one of the sensors 30, 32, 34. For example, the user 26 may change the direction of the device by moving the body part within and out of the predetermined operating range of each of the sensors 32, 34 within a predetermined time period (e.g., the user could move his head from left to right a predetermined number of times within a predetermined time period).
With reference to
The output signal is generated in a block 110 as a function of the determination made in the block 108. One component of the output signal represents the direction of the device 10. More specifically, if a left turn is indicated by the sensor 30 and a right turn is not indicated by the sensor 32, the direction component of the output signal indicates a left turn. Conversely, if a left turn is not indicated by the sensor 30 and a right turn is not indicated by the sensor 32, the direction component of the output signal indicates a right turn. Another component of the output signal represents the speed of the device 10. More specifically, the speed component of the output signal indicates a speed proportional to the distance of the body part from the center sensor 34; for example, a higher speed is indicated the farther the body part is from the sensor 34. However, if the body part is beyond a predetermined limit past the predetermined operating range of the sensor 30 (e.g., beyond the 5″ from the center sensor 34) and/or if the sensors 30, 32 call for both a left and a right turn, the speed component of the output signal is set to zero (0). This “autostop” feature is optional. If the “autostop” feature is not used, the device 10 will move a predetermined speed (e.g., the maximum speed) if the body part is moved beyond the predetermined limit (e.g., beyond the 2½″) from the center sensor 34.
The output control signal is transmitted from the controller 50 of the control module 22 to the rear wheels 18 in a block 112. If a left or right turn signal is included in the direction component of the output control signal, the wheels are controlled to cause the device to veer at a predetermined angel (e.g., 45°) toward the left or right side, respectively, while the speed of the device 10 is set as a function of the speed component of the output control signal.
In one embodiment, the speed of the wheels 18 is set independently of the direction. Therefore, the device 10 can veer at any speed; the determination of whether the device 10 veers is made as a function of the distance of the body part from the sensors 30, 32 while the determination of the speed is made as a function of the distance of the body part from the center sensor 34.
While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit of the applicant's general inventive concept.
This application is a continuation-in-part of U.S. patent application Ser. No. 10/273,320, filed Oct. 17, 2002, which claims benefit of U.S. Provisional Application No. 60/343,872, filed Oct. 19, 2001.
| Number | Date | Country | |
|---|---|---|---|
| 60343872 | Oct 2001 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10273320 | Oct 2002 | US |
| Child | 11779746 | US |
