Abstract:
An electronic enhanced mobility control interface of a mobility enhancement system implemented in a motor vehicle having a conventional electronic throttle control system. The electronic enhanced mobility throttle interface includes an auxiliary electronic throttle sensor in duplication of the conventional throttle pedal electronic throttle sensor, wherein the driver&#39;s selection of either the auxiliary or throttle pedal position throttle sensor is interfaced transparently to an engine electronic controller, as for example an engine control module (ECM/PCM) for processing to the electronic throttle control (ETC) subsystem. The electronic mobility enhancement throttle interface further includes an auxiliary throttle control by which the driver executes throttle commands to the auxiliary electronic throttle sensor, a data switch for connecting one or the other of the throttle pedal position and auxiliary electronic throttle sensors processing electronics to the ECM/PCM.

Description:
TECHNICAL FIELD 
     The present invention relates generally to motor vehicles equipped with an electronic throttle control, and further relates to motor vehicles equipped with a mobility enhancement system for drivers with physical disabilities. More particularly, the present invention relates to a mobility enhancement system featuring an electronic mobility enhancement throttle interface for the conventional electronic throttle control system of the motor vehicle. 
     BACKGROUND OF THE INVENTION 
     It is estimated that 88,082 U.S. drivers currently use mobility enhancement system hand controls for controlling vehicle operation, and that 43,623 U.S. drivers currently use a prosthetic aid for vehicle operation. Drivers requiring a mobility enhancement system for controlling vehicle operation are limited in their selection of hardware. Quite frequently, their selection involves thoughtful considerations regarding performance and convenience when attempting to address their specific needs. Often, their motor vehicle selection is limited to a small cross-section of products and is dictated by the available mobility enhancement control hardware. 
     Generally, drivers with disabilities who require a mobility enhancement system must settle for a purely mechanical mobility enhancement system, as exemplified by the mobility enhancement system  10  shown at FIGS. 1 through 4. In this regard, the mobility enhancement system  10  includes a mechanical brake pedal interface  10 ′ and a mechanical throttle pedal interface  10 ″. 
     In operation of the mechanical brake pedal interface  10 ′, the brake pedal  12  is actuated by directing a brake force F B  via the driver gripping a handgrip  16  and then downwardly pivoting a control arm  14 , whereby an interconnect member  18  applies the brake force onto the brake pedal. In operation of the mechanical throttle pedal interface  10 ″, the throttle pedal (commonly referred to as a “as pedal”)  20  is depressed by the driver applying a rotational movement (see arrow R) to the control arm  14 . The rotational movement is converted into a downward throttle pedal force F T  via a linkage assembly  22 , to thereby selectively depress the throttle pedal  20 . 
     For motor vehicles equipped with an electronic throttle control system  24 , a throttle pedal position electronic throttle sensor  28  is incorporated in a throttle pedal housing  26 . For example, the throttle pedal position electronic throttle sensor  28  is in the form of two potentiometers which, in conjunction with the position of the throttle pedal, provide throttle control information or a throttle control transfer function as analog inputs to an engine control module (ECM/PCM)  30  for processing the throttle (also referred to as “torque”) command to an electronic throttle control (ETC) subsystem  32 . 
     The force to depress the throttle pedal  20  is primarily dependent on return biasing of the throttle pedal by a pedal return spring which is associated with the throttle pedal housing  26 . To minimize the throttle pedal force F T  required to overcome this biasing force, the control arm  14  is lengthened to increase the mechanical advantage the physically disabled driver has over the pedal return spring. Because of the length of the control arm  14 , there is a need to minimize interference with interior vehicle components such as the inner door pull  34  and armrest  36  (see FIG.  2 ). Also taken into consideration is the potential for the downward rotational movement R of the control arm  14  to necessitate an accommodating repositioning of the driver&#39;s left leg (see FIGS.  2  and  3 ). 
     Accordingly, what is needed in the art is a mobility enhancement system for drivers with disabilities which has none of the disadvantages of current mechanical mobility enhancement throttle pedal interfaces. 
     SUMMARY OF THE INVENTION 
     The present invention is an electronic enhanced mobility control interface of a mobility enhancement system implemented in a motor vehicle having a conventional electronic throttle control system. The electronic enhanced mobility throttle interface includes an auxiliary electronic throttle sensor in duplication of the throttle pedal position electronic throttle sensor, wherein the driver&#39;s selection of either the auxiliary electronic throttle sensor or the throttle pedal position electronic throttle sensor is interfaced transparently to an engine electronic controller, as for example an engine control module (ECM/PCM) for processing to the electronic throttle control (ETC) subsystem. 
     The electronic mobility enhancement throttle interface includes, besides the aforementioned auxiliary electronic throttle sensor, an auxiliary throttle control by which the driver executes throttle commands to the auxiliary electronic throttle sensor and a data switch for connecting one or the other of the throttle pedal position electronic throttle sensor and the auxiliary electronic throttle sensor processing electronics to the ECM/PCM, wherein the auxiliary electronic throttle sensor is a functional duplicate of the throttle pedal position electronic throttle sensor. Accordingly, selection by the driver of either the auxiliary electronic throttle sensor or the throttle pedal position electronic throttle sensor is transparent to the ECM/PCM for processing as throttle commands to the ETC subsystem, wherein the throttle pedal position electronic throttle sensor is the default selection. 
     The present invention provides for minimal force application to effect throttle commands, eliminates the need to mechanically depress the existing throttle pedal, and provides for the choice of utilizing the conventional throttle pedal or the auxiliary throttle control for executing throttle commands. 
     The present invention also prevents a change of source of throttle command as long as the ignition switch is turned on. Additionally, a time-out is preferably provided which times from selection of a source of throttle command to turning on of the ignition switch, and defaults to the throttle pedal position electronic throttle sensor in the event of a time-out before the ignition switch is turned on. 
     Accordingly, it is an object of the present invention to provide a mobility enhancement system for physically disabled drivers which features an electronic mobility enhancement throttle interface including an auxiliary electronic throttle sensor in duplication of the conventional throttle pedal position electronic throttle sensor. 
     This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a first perspective view of a prior art mechanical mobility enhancement system. 
     FIG. 2 is a second perspective view of the prior art mechanical mobility enhancement system of FIG.  1 . 
     FIG. 3 is a side view of prior art mechanical mobility enhancement system of FIG.  1 . 
     FIG. 4 is a block diagram of the prior art mechanical mobility enhancement system interfaced to a motor vehicle equipped with an electronic throttle control system. 
     FIG. 5 is a perspective view of an example of the preferred environment of use of a mobility enhancement system according to the present invention. 
     FIG. 6 is a block diagram of the mobility enhancement system of FIG. 5 interfaced to a motor vehicle equipped with an electronic throttle control system. 
     FIG. 7 is a functional block diagram for carrying out operation of an electronic mobility enhancement throttle interface of the mobility enhancement system of FIG.  6 . 
     FIG. 8 is an example of an electronic circuit for implementing the functional block diagram of FIG.  7 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the Drawings, FIGS. 5 through 8 depict various aspects of an electronic mobility enhancement system  100  according to the present invention which includes an electronic mobility enhancement throttle interface  102 . 
     FIG. 5 depicts an example of the preferred environment of use of the mobility enhancement system  100  incorporated into a motor vehicle equipped with an electronic throttle control system  24 . In this example, the electronic mobility enhancement interface  102  consists of an auxiliary throttle control  104  (as for example a hand operated twist grip  104 ′) which allows a driver to select throttle commands to an auxiliary electronic throttle sensor  108  (for example located in the twist grip  104 ′), a data switch  110  including processing electronics, first and second throttle signal connections  112   a ,  112   b  from, respectively, each of the auxiliary electronic throttle sensor  108  and the conventional throttle pedal position electronic throttle sensor  28  to the data switch  110  (located within a data box  110 ′), an activation switch  114  for driver selection of the auxiliary electronic throttle control sensor at the data switch, and an electrical connection  116  from the data switch to the ECM/PCM  30 . Preferably, the electronic mobility enhancement interface  102  further includes a time-out latch  118  electrically interfaced with the ignition switch  120 , the activation switch  114  and the data switch  110 . The latch  118  serves as a safety feature by preventing a change of source of throttle command as regards the throttle pedal position electronic throttle sensor  28  and the auxiliary electronic throttle sensor  108 , as long as the ignition switch is turned on. In operation, before the ignition switch is turned on, the driver can select which one of the auxiliary electronic throttle sensor  108  and the throttle pedal position electronic throttle sensor  28  is to be interfaced with the vehicle ECM/PCM  30  for processing as the throttle input command to the ETC subsystem  32 . 
     Per the present example, the auxiliary electronic throttle sensor  108  is located within the twist grip  104 ′, and the twist grip is rotatably mounted to a control arm  14 ′. Where present, the control arm may serve the above described mechanical braking function relative to a mechanical brake pedal interface  10 ′. The auxiliary electronic throttle sensor  108  duplicates the throttle pedal position electronic throttle sensor  28  which is connected to the throttle pedal  20 . For example, each of the throttle pedal position electronic throttle sensor  28  and the auxiliary electronic throttle sensor  108  consist, in the present example, of two potentiometers. When the auxiliary electronic throttle sensor  108  has been selected by the driver, desired amounts of rotation of the twist grip provide desired throttle commands to the ECM/PCM  30 . In this regard, the ECM/PCM  30  interfaces transparently (that is, identically) with either of the auxiliary or throttle pedal position electronic throttle sensors  108 ,  28 . 
     It is understood that the auxiliary electronic throttle sensor  108  may consist of single or multiple contacting or non-contacting control devices (mechanical, optical, magnetic, etc.) whereby the driver can vary the throttle commands to the ECM/PCM  30  with a transfer function identical to the throttle pedal position electronic throttle sensor  28 . Also, the auxiliary throttle control  104  may be, besides the twist grip  104 ′, a squeeze lever, a thumb button, a left foot throttle, or other control, wherein the activation switch may be incorporated within the auxiliary throttle control, or elsewhere. 
     The first throttle signal connection  112   a  provides power and signal transfer between the auxiliary electronic throttle sensor  108  and processing electronics of the data switch  110 . If the auxiliary electronic throttle sensor  108  is selected by the driver via actuation of the activation switch  114 , the processing electronics of the data switch  110  passes throttle commands (also referred to as “torque commands”) from the auxiliary electronic throttle sensor as inputs to the ECM/PCM  30  for processing as the throttle (torque) input command to the ETC subsystem  32 , and passes power from the ECM/PCM to the auxiliary electronic throttle sensor. 
     However, if the throttle pedal position electronic throttle sensor  28  is selected (as for example by driver default or by time out of the latch  118 ), the processing electronics of the data switch  110  passes throttle commands (torque commands) from the throttle pedal position electronic throttle sensor  28  as inputs to the ECM/PCM  30  for processing as the throttle (torque) input command to the ETC subsystem  32 , and passes power from the ECM/PCM to the throttle pedal position electronic throttle sensor via the second throttle signal connection  112   b . The latch  118  interfaces with the processing electronics of the data switch  110  to provide a safety feature which prevents a change in selection of the throttle pedal position and auxiliary electronic throttle sensors  28 ,  108  while the ignition switch is turned on. 
     FIG. 7 is a functional block diagram for implementing the present invention and starts at Block  140 . If the auxiliary electronic throttle sensor  108  is not selected at Block  142 , and if the ignition switch is turned on at Block  144 , then a latch is set at Block  146  for retaining the throttle pedal position electronic throttle sensor commands, whereby the throttle sensor commands are passed to the ECM/PCM  30  at Block  148 . The throttle pedal position electronic throttle sensor commands continue to be passed to the ECM/PCM at Block  148  through Block  150  until the ignition switch is turned off at Block  150 , at which time the latch set in Block  146  is reset at Block  152 , and the process ends at Block  154 . Revisiting Block  144 , if the ignition switch was not turned on at Block  144 , then control passed back to Block  142 . 
     If the driver selects the auxiliary electronic throttle sensor  108  via actuation of the activation switch  114  prior to turning on the ignition switch at Block  142 , then control passes to Block  156 . If the auxiliary electronic throttle sensor  108  selection at Block  142  times-out at Block  156  (as for example a 10 second delay between actuation of the activation switch  114  and turning on of the ignition switch  120 ), then control passes to Block  144  and proceeds as previously described. If, however, the selection at Block  142  does not time out at Block  156  and the ignition switch has not yet been turned on at Block  158 , control passes back to Block  156  awaiting either a time-out at Block  156  (as described) or the turning on of the ignition switch at Block  158 . Now, if the ignition switch is turned on at Block  158  before a time-out at block  156 , then the latch  118  is set at Block  160  for retaining auxiliary electronic throttle sensor commands, whereby the throttle sensor commands are subsequently passed to the ECM/PCM  30  at Block  162  through Block  164  until the ignition switch  120  is turned off at Block  164 , at which time the latch set in Block  160  is reset at Block  166 , and the process ends at Block  168 . 
     FIG. 8 is an example of an electronic circuit  170  for implementing the functional block diagram of FIG.  7 . Within the data switch  110  is a Relay  174 , which is a 4-pole double-throw (4PDT) relay shown in its de-energized (or deactivated) state. The Relay  174  provides the interface to the ECM/PCM  30  and selects alternatively one or the other of the throttle pedal position electronic throttle sensor  28  and the auxiliary electronic throttle sensor  108 , under control of Q 1  and Q 2 . V 1  and V 2  are 5-volt control signals generated by the ECM/PCM  30  when the ignition switch is turned on and both are either supplied, depending on the state of the Relay  174 , to the two potentiometers (per this example) of the throttle pedal position electronic throttle sensor  28  as V P1  and V P2 , or the two potentiometers (per this example) of the auxiliary electronic throttle sensor  108  as V D1  and V D2 , respectively. In this regard the two potentiometers of each electronic throttle sensor  28 ,  108  are identical. I 1  and I 2  are the throttle (or torque) input to the ECM/PCM  30  from either the throttle pedal position electronic throttle sensor  28  or the auxiliary electronic throttle sensor  108 , as determined by the state of the Relay  174 . The +12V voltage supply is available independent of the on/off state of the ignition switch. 
     If the activation switch  114  is not actuated and the ignition switch is turned off, Q 1  is biased on through 10 kilo-ohm resistor R 1 , but Q 2  is biased off through 10 kilo-ohm resistor R 2  preventing the Relay  174  from being energized, and thereby selecting the throttle commands P 1  and P 2  from the throttle pedal position electronic throttle sensor  28  as the inputs I 1  and I 2  to the ECM/PCM  30  through the Relay  174 . However, if the ignition switch is turned on, the ECM/PCM  30  provides 5-volt control signals V P1  and V P2  to the throttle pedal position electronic throttle sensor  28  from the ECM/PCM  30  through the Relay  74 , whereby the 5-volt control signal V P1  is input to the non-inverting terminal of an operational amplifier  176  whose output, passed by diode D 3 , biases Q 1  off and ensures that Relay  174  remains de-energized and the throttle pedal position electronic throttle sensor remains selected until the ignition switch is turned off, regardless of the subsequent on/off state of the activation switch  114 . When the ignition switch is turned off, Relay  174  remains de-energized. 
     Actuating the activation switch  114  activates a Timer  178  of Latch  118 , in this example a 555 timer, for a predetermined time period, for example ten seconds. Q 1  is biased on through 10 kilo-ohm resistor RI, and Q 2  is biased on by the output of the Timer  178  through D 5  and 10 kilo-ohm resistor R 3  connected to the base of Q 2 , by which the Relay  174  is energized, thereby selecting the throttle commands D 1  and D 2  from the auxiliary electronic throttle sensor  108  as the inputs I 1  and I 2  to the ECM/PCM  30  through the Relay  174 . The auxiliary electronic throttle sensor  108  has an electronic function similar to the throttle pedal position electronic throttle sensor  28 , whereby the ECM/PCM  30  transparently sees either. If the ignition switch is turned on before the Timer  178  times out, Q 1  remains biased on through a 10 kilo-Ohm resistor R 1  and the ECM/PCM  30  provides 5-volt control signals V D1  and V D2  to the auxiliary electronic throttle sensor  108  from the ECM/PCM  30  through the Relay  174 , whereby the 5-volt control signal V D1  passed by diode D 5  and 10 kilo-ohm resistor R 4  biases Q 2  on, ensuring that the Relay  174  remains energized and the auxiliary electronic throttle sensor  108  remains selected until the ignition switch is turned off, regardless of the subsequent state of the activation switch  114 . When the ignition switch is turned off, Q 2  is biased off and the Relay  174  is de-energized. However, if the Timer  178  has timed-out before the ignition switch is turned on, Q 2  is biased off and the Relay  174  is de-energized, whereby the activation switch  114  must be again actuated with the ignition switch off in order to reselect the auxiliary electronic throttle sensor as the input to the ECM/PCM  30 . In the foregoing, the on/off states of the ignition switch may also be regarded as first and second states of the engine. 
     To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.