Abstract:
A system for adjustably positioning foot pedals with respect to a vehicle chassis, such as to improve ergonomics or to appropriately space a vehicle occupant with respect to a vehicle safety system. The system includes first and second electromagnetic actuators, first and second controllers, and a device, which may be a switch disposed on the vehicle chassis, provides a signal to change spacing between the vehicle chassis and the plurality of pedals. The first electromagnetic actuator displaces a first pedal with respect to the vehicle chassis, and the second electromagnetic actuator displaces a second pedal with respect to the vehicle chassis. The first controller operates the first electromagnetic actuator in response to the configuration of the device, and the second controller operates the second electromagnetic actuator in response to the first controller operating the first electromagnetic actuator.

Description:
FIELD OF THE INVENTION  
       [0001]     An adjustable pedal assembly is used in an automotive vehicle to vary the operating position of one or more of the foot pedals that control various vehicle systems, such as the engine throttle, brake system and clutch.  
       BACKGROUND OF THE INVENTION  
       [0002]     A known adjustable pedal assembly uses an electrical motor to rotate a drive cable that, in turn, rotates a worm gear to adjust the position of a pedal. Other known assemblies eliminate the cable and connect the worm gear more directly to a pedal lever. These known systems are believed to suffer from a number of disadvantages, which include large numbers of parts, excessive noise and imprecise output. Another disadvantage of these know assemblies is believed to be the large size requirements within the tight confines of the driver&#39;s footwell.  
         [0003]     In accordance with the standards that have been promulgated by various government regulatory agencies as to the position of the brake pedal relative to the position of the engine throttle control pedal, some known assemblies use one motor to drive the adjustment of more than one pedal.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention provides a system that adjustably positions a plurality of pedals, including an engine throttle control pedal and a brake system pedal, with respect to a vehicle chassis. The system includes first and second electromagnetic actuators, first and second controllers, and a device that provides a signal to change spacing between the vehicle chassis and the plurality of pedals. The first electromagnetic actuator displaces a first one of the engine throttle control and brake system pedals with respect to the vehicle chassis, and the second electromagnetic actuator displaces a second one of the engine throttle control and brake system pedals with respect to the vehicle chassis. The device, which is disposed on the vehicle chassis, has a first configuration that provides a first signal to increase the spacing between the vehicle chassis and the first and second pedals, and a second configuration that provides a second signal to decrease the spacing between the vehicle chassis and the first and second pedals. The first controller operates the first electromagnetic actuator in response to the device being positioned in either of the first and second configurations, and the second controller operates the second electromagnetic actuator in response to the first controller operating the first electromagnetic actuator.  
         [0005]     The present invention also provides a system that adjustably positions with respect to a vehicle chassis a plurality of pedals, which may include an engine throttle control pedal and a brake system pedal. The system includes first and second electromagnetic actuators, first and second controllers, and a device that provides a signal to change spacing between the vehicle chassis and the plurality of pedals. The first electromagnetic actuator displaces a first one of the engine throttle control and brake system pedals with respect to the vehicle chassis, and includes a first housing. The second electromagnetic actuator displaces a second one of the engine throttle control and brake system pedals with respect to the vehicle chassis, and includes a second housing that is spaced from the first housing. The device, which is disposed on the vehicle chassis, has a first configuration that provides a first signal to increase the spacing between the vehicle chassis and the first and second pedals, and a second configuration that provides a second signal to decrease the spacing between the vehicle chassis and the first and second pedals. The first controller operates the first electromagnetic actuator in response to the device being positioned in either of the first and second configurations. The second controller operates the second electromagnetic actuator in response to the first controller operating the first electromagnetic actuator.  
         [0006]     The present invention also provides a system that adjustably positions with respect to a vehicle chassis a plurality of pedals, which may include an engine throttle control pedal and a brake system pedal. The system includes first and second electromagnetic actuators, first and second controllers, and a device that provides a signal to change spacing between the vehicle chassis and the plurality of pedals. The first electromagnetic actuator displaces a first one of the engine throttle control and brake system pedals with respect to the vehicle chassis, and includes a first housing. The second electromagnetic actuator displaces a second one of the engine throttle control and brake system pedals with respect to the vehicle chassis, and includes a second housing that is spaced from the first housing. The device, which is disposed on the vehicle chassis, has a first configuration that provides a first signal to increase the spacing between the vehicle chassis and the first and second pedals, and a second configuration that provides a second signal to decrease the spacing between the vehicle chassis and the first and second pedals. The first controller, which is disposed in the first housing, operates the first electromagnetic actuator in response to the device being positioned in either of the first and second configurations. The second controller, which is disposed in the second housing, operates the second electromagnetic actuator in response to the first controller operating the first electromagnetic actuator. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate presently preferred embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain features of the invention. Like numerals indicate like or corresponding parts throughout the several views.  
         [0008]      FIG. 1  is schematic view of an adjustable pedal system according to a preferred embodiment.  
         [0009]      FIG. 2  is a isometric view of a preferred embodiment of an apparatus for adjustably positioning a foot-operated control with respect to a vehicle chassis.  
         [0010]      FIG. 3  is an axial longitudinal view of the preferred embodiment of an apparatus shown in  FIG. 2 .  
         [0011]      FIG. 4  is an axial end view of the preferred embodiment of an apparatus shown in  FIG. 2 .  
         [0012]      FIG. 5  is an exploded isometric view of the preferred embodiment of an apparatus shown in  FIG. 2 .  
         [0013]      FIG. 6  is a cross-section taken along line VI-VI in  FIG. 4 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0014]     Referring initially to  FIG. 1 , an adjustable pedal assembly is generally shown at  10 . The adjustable pedal assembly  10  is shown as having a common pivot axis  12  with respect to a vehicle chassis, which is schematically indicated at  12   a ; however, the pivot axes for different pedals may not be collinear.  
         [0015]     A first pedal lever  20   a  is pivotally supported for rotation about the pivot axis  12  with respect to the vehicle chassis  12   a . Similarly, a second pedal lever  20   b  and a third pedal lever  20   c  are also pivotally supported for rotation about the pivot axis  12  with respect to the vehicle chassis  12   a .  FIG. 1  shows three pedal levers  20   a , 20   b , 20   c , which may be operatively associated with an engine throttle control system  14 , a brake system  16 , and a clutch  18 , respectively. However, there may be fewer than three pedal levers, e.g., in the case of a vehicle equipped with an automatic transmission such that there would be only first and second pedal levers  20   a , 20   b , or more than three pedal levers, e.g., additionally including a foot-operated parking brake. For each pedal lever  20   a , 20   b , 20   c  there is a pedal  22   a , 22   b , 22   c , respectively, which is engaged by a vehicle operator&#39;s foot. The particulars of a pedal lever are described in U.S. patent application Ser. No. ______ (“Actuator Apparatus Incorporating a Controller;” Attorney Docket No. 2004P18022US), which is hereby incorporated by reference in its entirety.  
         [0016]     Interconnecting a pedal lever and a corresponding pedal is an actuator  30   a , 30   b , 30   c  that displaces the respective pedal relative to the pedal lever. Each actuator may include a drive source, such as an electric motor, and may include a linkage, such as a rotary to linear motion converter. Relative displacement is directed by guides  31   a , 31   b , 31   c , which may be tubular with longitudinal slots. U.S. Pat. Nos. 5,722,302 and 5,964,125 and 6,698,309, which show a drive source and a linkage for an adjustable pedal, are hereby incorporated by reference it their entireties.  
         [0017]     Referring now to  FIGS. 2-6 , there is shown a preferred embodiment of an actuator  30  including an electrically operated motor  32  providing a rotary drive source. The electric motor  32  may sequential move in discrete angular increments, e.g., a stepper motor, or may move in a continuous manner, e.g., a brushless motor. Preferably, the motor  32  rotates a threaded rod  40 , which results in linear displacement of a nut  42  that is cooperatively engaged with the threaded rod  40 . Alternatively, the motor  32  could rotate a nut causing linear displacement of a cooperatively engaged threaded rod. Further, other types of rotary to linear motion converters, e.g., rack and pinion gearing or worm gearing, could be used to displace a pedal  22  with respect to a lever  20 .  
         [0018]     The motor  32  is preferably constructed with a stator  34  that has a plurality of windings or coils  34   a  (e.g., one of three is shown in  FIG. 6 ) that are angularly spaced around the axis of rotation (e.g., 120 degrees), and an armature  36  that includes a permanent magnet  36   a . As is well understood, sequentially energizing and de-energizing each of the coils  34   a  set up individual magnetic fields that either attract or repulse the permanent magnet  36   a , thereby causing the armature  36  to rotate. At the same time, rotation of the permanent magnet  36   a  induces in the coils  34   a  a current that can be used to determine angular movement, e.g., number of rotations of the armature  34 . The phenomenon that creates this current is commonly referred to as back electro-motive force, or back emf.  
         [0019]     The motor  32  is disposed in a housing  50  that preferably supports the threaded rod  40  for relative rotation. Antifriction devices such as a bearing  52  may be used at the interface of the threaded rod  40  and the housing  50 . The housing  50  preferably includes a body portion  54 , in which the motor  32  is disposed, and a coupling portion  56 , by which the electrical connections are made with the motor  32 . In order to facilitate assembly of the actuator  30 , at least the body portion  54  of the housing  50  may be assembled from more than one piece. As particularly shown in  FIG. 3 , the body portion  54  may preferably be divided into a front piece  54   a  and a back piece  54   b . An insert molded lead frame  58  may be disposed in the bottom of the back piece to make the electrical connections with the coils  34   a.    
         [0020]     The coupling portion  56  of the housing  50  preferably includes an enclosure portion  56   a  for a controller  60 , and an interchangeable electrical connector portion  56   b , which is preferably detachable with respect to the enclosure portion  56   a . The interchangeable electrical connector portion  56   b  facilitates providing various configurations of electrical contacts to matingly engage different styles of plug connectors. It is envisioned that the body portion  54  and the enclosure portion  56   a  would be universally used, and a particular interchangeable electrical connector portion  56   b  would be selected according to the particular specification of the manufacturer for the vehicle chassis  12   a.    
         [0021]     The controller  60  that is disposed in the enclosure portion  56   a  of the coupling portion  56  preferably includes an application-specific integrated circuit (ASIC)  62  that can perform at least two functions: 1) driving the coils  34   a , and 2) determining displacement of the pedal  22  with respect to the vehicle chassis  12   a . The first function is commonly referred to as a motor drive circuit. And the second function is performed by a processor based on the number of rotations of the armature  34 , which is determined using back emf, as discussed previously, and the stored knowledge of the thread pitch of the threaded rod  40 . The controller  60  preferably also includes a memory for different operational positions of the pedal  22 , such as for the preferences of different operators of the vehicle.  
         [0022]     In the event of a loss of the current operational position of the pedal, e.g., due to the motor  32  stalling, the controller  60  detects the stall and adjusts the pedal lever position or shuts down the respective actuator  30   a , 30   b , 30   c  so as to maintain the existing relationship between the corresponding pedal lever  20   a , 20   b , 20   c  and pedal  22   a , 22   b , 22   c . When the controller  60  detects stall of the motor  32 , e.g., based on unusual voltage and time characteristics exhibited by the drive circuit, the controller  60  may use an included software program to reestablish the predetermined relationship between the pedals  22   a , 22   b , 22   c , or to reset the adjustable pedal system  10  by displacing all of the petals  22   a , 22   b , 22   c  to their extreme positions, as detected by the motors  32  stalling.  
         [0023]     In the case of the adjustable petal system  10 , it is desirable that adjustment of the actuators  30   a , 30   b , 30   c  be synchronized. A controller  60  for one of the actuators, e.g.,  30   a , is designated as the “master” controller, and sends signals to the “slave” controllers of the other actuators  30   b , 30   c . The master may send disproportionate signals to the slave(s) in order to maintain the correct relative position of pedals  22   a , 22   b , 22   c.    
         [0024]     In operation, a device for adjusting the position of the pedals  22   a , 22   b , 22   c  can be effected by a switch, e.g., a rocker switch, that is manually actuated by the operator of the vehicle, or can be effected by a body controller unit which may interrelate a number of ergonomic and safety adjustments. For example, in the case of a vehicle equipped with a system of airbags, the body control unit may adjust the seat and pedal positions so that an occupant is a prescribed distance from the airbags.  
         [0025]     An adjustable petal system  10  that uses a body control unit may require as few as three electrical contacts for each actuator  30 : a power contact, a ground contact, and a communication contact. The power and ground contacts supply the power required by the motor  32 , and the communication contact may be connected via a digital serial communication link to the body control unit and to the communication contacts of additional actuators  30 . In the case of a manual switch, two additional contacts may be required to connect the master actuator  30  with the wire from the increase spacing pole of the switch and with the wire from the decrease spacing pole of the switch; the communication contact would still be used by the master and slave actuators to communicate status regarding position, displacement speed, etc.  
         [0026]     Incorporating a master or slave controller  60  that is mounted directly on each actuator  30  provides the present invention with a number of advantages. First, the present invention eliminates a separate controller that is additionally mounted on the chassis and then additionally connected to each of the actuators. Second, by virtue of having self-contained processing power, the present invention eliminates the need to draw processing capacity from other preexisting processors, e.g., engine control unit. Third, the present invention eliminates the need for a custom actuator for each pedal of each vehicle manufacturer, i.e., the actuator units are manufactured identically, and only distinguished as to master and slave roles during or after installation on the vehicle. Fourth, by virtue of the controller  60  processing the back emf signals from the coils  34   a , the present invention eliminates the need for additional motor rotation sensors, e.g., an array of Hall effect sensors, which add cost, complexity and size. Fifth, by virtue of the controller  60  processing the back emf signals from the coils  34   a , the present invention eliminates at least four wires from the wiring harnesses connecting each actuator  30 . Sixth, the interchangeable electrical connector portion  56   b  of the present invention facilitates the universal applicability of the actuator  30  while providing an easy manner of adapting to varying styles of electrical plug connectors.  
         [0027]     While the present invention has been disclosed with reference to certain preferred embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the present invention, as defined in the appended claims. Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims, and equivalents thereof.