Abstract:
An automated system for cycling vehicle lamps on and off allows direct inspection by one person of operability of the lamp bulbs while doing a walk around of the vehicle. The system is switch operated. Interlocks to operation are based upon the status of the vehicle&#39;s service brake, its park brake and the on/off status of the lights themselves. Lights are organized by related groups and each group given a distinctive, repeating cycle to lighten the burden of memorization on the operator.

Description:
BACKGROUND OF THE INVENTION 
   1. Technical Field 
   The present invention relates generally to commercial motor vehicles and more particularly to an automated system for cycling vehicle lamps on and off to allow direct sight inspection by one person of operability of the lamp bulbs during a vehicle walkaround. 
   2. Description of the Problem 
   Federal regulations governing commercial vehicles and school busses provide for periodic inspection of various vehicle systems. Among the vehicle systems requiring inspection are exterior lamps, such as headlights, turn indicator lamps and identification lights. An inspection must determine not only if the lamp is operable, but that systems for actuating lamps for indicating turns, braking, or for flashing, are also functioning correctly. Performing such checks has generally been much easier if two people are available to make the check, one to remain in the cab of the vehicle to depress the brakes, activate turn signals and perform other similar operations while another person walks around the vehicle to view the lamps&#39; operation. Where only one person, typically the driver, is available, such checks can be quite onerous. 
   Partial automation of a exterior light inspection procedure was proposed in U.S. Pat. No. 6,674,288, which is incorporated herein by reference. The Vehicle Lamp Inspection System proposed there provided for the automatic activation and deactivation of a vehicle&#39;s exterior lights in accordance with a predetermined sequence. The system was implemented over a programmable electrical system controller, programmed to implement a repeating test program in response to a user request. 
   SUMMARY OF THE INVENTION 
   According to the invention there is provided a vehicle lamp exercise feature. The lamp exercise feature provides cycling on and off of a plurality of lamps mounted to be visible on the exterior of the vehicle. The lamps are organized into functional subsets of lamps. An electrical system controller has a plurality of lamp energization output ports with an energization circuit for each functional subset of lamps, each energization circuit being connected to a different one of the lamp energization outputs. A first set of lamp activation switches for some of the functional subsets of lamps, and service brake position and parking brake position switches, are connected to the electrical system controller to provide status inputs to the electrical system controller. A gauge controller provides input points for a second set of lamp activation switches, including a lamp test switch. An ignition switch position sensing element provides a further a control input to the gauge controller. A datalink between the gauge controller and the electrical system controller allows indications of the state of status and control inputs received by the gauge controller to be communicated to the electrical system controller. The electrical system controller further includes a programmable microcomputer for switching on and off each of the plurality of energization output ports. A test program executable on the programmable microcomputer is responsive to actuation of the lamp test switch for execution. The test program includes program means for grouping selected functional subsets of lamps. The test program further provides means for sequentially activating and extinguishing the lamps of each functional subset within a group undergoing testing by selective energization of the lamp energization output ports. Further program means are responsive to detection that the park brake is set, the ignition switch position is on and all exterior lamp energization output ports are off to allow the test program to proceed upon detection of activation of the exterior lamp check switch. Still further program means provide for detecting a change in state of one of the brake position switch, the park brake position switch, or a lamp activation switch for terminating execution of the test program. 
   Additional effects, features and advantages will be apparent in the written description that follows. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
       FIG. 1  is a perspective view of a school bus equipped with lighting systems with which the present invention is advantageously employed. 
       FIG. 2  is a simplified front elevation of a bus instrument panel. 
       FIG. 3  is a high level schematic of the lighting connections for an electrical system controller. 
       FIG. 4  is a circuit schematic for a motor vehicle lighting system and related controls. 
       FIG. 5  is a flow chart of a program executed on the electrical system controller for implementing the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the drawings and in particular referring to  FIG. 1  a school bus  10  is shown. An assortment of lamps are mounted to or to be visible on the exterior of school bus  10 , including, but not limited to headlamps  12 , front turn signals  14 , front flashers  16  and side marker lights  18 . 
   Referring to  FIG. 2 , an instrument panel  20  is positioned at a driver&#39;s station in the interior of school bus  10 . Execution of the lamp check routine of the present invention is initiated, in part, by cycling of a switch  24  mounted in a switch array  22  at the lower left portion of the panel  20 . A lamp  26  set in the switch  24  is illuminated to indicate when the program of the present invention is executing or a request for execution has been made. 
     FIG. 3  illustrates lighting pin connections for a programmable electrical system controller (ESC)  30  and selected input connections. ESC  30  is a high level controller for an vehicle controller area network. ESC  30  directly energizes most vehicle exterior lamps including, by group: the lowbeam headlights; the highbeam headlights; the marker lights; the left front and rear red pupil warning lights (PWL); the right front and rear red PWL; the right front amber PWL; the left front amber PWL; the left rear amber PWL; the right rear amber PWL; the left front turn signals; the right front turn signals; the right rear turn signals; the left rear turn signals; the stop lights; and, the reverse lights. ESC  30  is connected to receive directly a park brake position signal input and the PWL input from a resistor switching network. ESC  30  receives an ignition input signal from an ignition switch  331  over a controller area network bus. 
     FIG. 4  is a partial circuit schematic of an electrical gauge controller (EGC)  40 , ESC  30 , and some of the plurality of lamps energized under the control of the ESC. Several power switching Field Effect Transistors (FETs) used for energizing various lamps are illustrated. Fewer than the number of FETs required are illustrated because the specific circuit element is simply repeated up to the number of lamp circuits for which support is required. ESC  30  is a programmable body systems computer used to control many vehicle electrical system functions, most of which are not shown. In the past, many of these functions were controlled by switches, relays and other independently wired and powered devices. ESC  30  is based on a microprocessor  31  which executes programs and which controls switching of the plurality of power FETs  52 ,  53 ,  54 ,  55 ,  56 ,  57  and  58  used to actuate vehicle exterior lights. Among those lights, and explicitly illustrated here are a park and marker light circuit  37  and an ID light circuit  38 , which are energized by Park Light FET  52  and the low and high beam headlights  61 ,  48 , which are energized by FETs  53  and  54 , respectively. Yet another power FET  51  is used to energize a horn coil  36 . One FET may be used to drive the indicator light  26  in the exterior light test switch  24 . This allows indicator light  26  to flash during testing, and other certain other conditions. 
   Microprocessor  31  can apply activation signals to all of the lamps subject to inspection as well as to a horn coil  36 . In the case of headlights  61 ,  48  this may also involve pulling high a headlight enable line by instruction to EGC  40 . Microprocessor  31  is connected to provide an activation signal to a horn power FET  51  which in turn drives a horn coil  36 . Another signal line from microprocessor  31  is connected to drive a park light FET  52  which in turn drives park/marker light bulbs  37  and license plate ID bulbs  38 . Yet another signal line from microprocessor  31  drives a low beam FET  53 , which in turn drives filaments in headlight bulbs  48 . Low beam FET  53  and park light FET  52  further require an Input on the headlight enable line to operate. Still another pin on microprocessor  31  controls a high beam FET  54  which drives high beam filaments in bulbs  61  and  48 . Remaining pins on microprocessor  31  are used to control the remaining lights of the vehicle. Four FETs  55 ,  56 ,  57  and  58  are illustrated as connected to receive the signals and, in turn, to power bulbs  63 ,  64 ,  65 , and  46 . However, those skilled in the art will realize now that any number of FETs and bulbs may be connected. Flasher operation may also be readily simulated. 
   Inputs to ESC  30  come from various sources. Primary among these is the electric gauge controller (EGC)  40 , which provides local control and a controller area network interface over the instruments and switches installed on instrument panel  20 . EGC  40  communicates with ESC  30  over a CAN data link (bus  60 ) which conforms to the SAE J1939 standard. CAN controllers  43  and  143  located with EGC  40  and ESC  30 , respectively, implement the network protocols and data packet decoding. EGC  40  is based on a microprocessor  41  but includes only limited and typically fixed programming. EGC  40  handles an array of microswitches  45 , and is programmed to provide manual control over headlights, park lights, marker lights, etc., as well as provide for initiation of the test cycles of the present invention, using the microswitches. Sources of direct inputs to ESC  30 , relevant to the operation of the present invention, include a park brake  140 , brake  136 , possible horn  138  and a pupil warning light resistive network  222 . The resistor network  222  is adapted from switches supplied to implement a speed control system. Naturally, other arrangements may be made for turning on the PWL. 
   Activation of a lamp test routine begins with cycling of one of the switches in microswitch array  45 , with is detected by EGC  40  and broadcast over bus  60  for detection by ESC  30 . Microprocessor  31  then begins sequences of actuation of the FET switches to illuminate the various lamps in accordance with predetermined routines. The test routine also requires, as a precondition, that the park brake  140  be set, all lights being checked are off, and the ignition key is in the ‘ON’ position. Cancellation of the cycle occurs upon anyone of the following: (1) tapping or depressing the brake pedal  136 ; (2) release of the park brake  140 ; (3) moving the ignition key to the start or off positions; or (4) turning on any of the lights that are in the sequence. The preconditions force the vehicle to be immobilized before the sequence can begin. 
     FIG. 5  is a high level flow chart which illustrates the testing cycles for the lamps. To initiate testing, as indicated at step  500 , all exterior lamps are turned off, the key is in the ignition and moved to the ON position, the park brake is set and the exterior lamp check switch  24  is pressed. This set of preconditions for execution of the test program should prevent accidental initiation of the program, for example, when the vehicle is being driven. The test routine is divided into three subroutines  510 ,  520 ,  540 , which are associated with different groups of lights, organized logically by function to assist the operator in his visual inspection walk around. Each subroutine may be programmed to execute repetitively for a predetermined time period, for example two minutes, with each light energization step lasting a few seconds, before the next subroutine is executed. Or, the three subroutines may be programmed to execute in parallel. 
   Subroutine  510  handles marker and signaling lights. At step  511  the left and right turn signals, marker lights and stop lights are energized. Next, following a one second delay (step  512 ), a subset of these lights, including the left and right turn signal lights and the stop lights are turned off (step  513 ). Following a further one second delay (step  514 ) the marker lights are turned off (step  515 ). Then, yet another one second delay is executed (step  516 ) and the subroutine returns to step  510 . 
   Subroutine  520  handles the pupil warning light (PWL) group. At step  521  the left red PWLS are turned on and the right red PWLS are turned off. A one second delay (step  522 ) is then executed. Next, at step  523 , the left amber PWLS are turned on and the left red PWLS are turned off. Again a one second delay is executed (step  524 ). Then, at step  525 , right amber PWLS are turned on and the left amber PWLS are turned off. Following a one second delay (step  526 ) step  527  is executed to turn on the right red PWLS and to turn off the right amber PWLS. Then a one second delay is executed at step  528  and execution is returned to step  521 . 
   Subroutine  540  relates to the light group associated with aiding the driver&#39;s sight, i.e. the headlights, foglights and backup lights. Step  541  provides for turning on the highbeams and turning off the lowbeams, fog lamps and back up lights. Step  542  is a three second delay, followed by step  543  where the lowbeams, fog lamps and back up lights are illuminated and the high beams are extinguished. Step  544  provides for another three second delay and execution is returned to step  541 . 
   Step  550  is applicable to all three subroutines and provides for disengagement of the subroutines. Upon occurrence of any of four events the routines cease execution, including, press and release of the brake pedal, release of the park brake, turning the ignition key to the off or crank positions, or manually turning on any light in the test sequences. Automatic disengagement assures that the light sequence will turn off when the driver begins driving the vehicle. In addition, the routine may be exited by turning the process off using switch  24 . 
   Each subroutine defines a group of lamp sets. A unique pattern of illumination and extinguishment of lamps characterizes each group, making the task of remembering which functional sets of lamps belong to each group, and better assuring that an operator does not miss one of the functional sets during walk-around of the vehicle. Patterns are marked by varying when sets are turned on and off with respect to one another from set to set and by varying the delays built into the cycling program for each group. The number of functional sets in each group is limited to four. 
   The invention provides for simplification of operator inspection of vehicle exterior lamps by through the automatic, sequential and repeated illumination and extinguishment of lamps. Sets of lamps are associated with one another into groups to present an easily recalled hierarchy to the user, and eliminating the need to remember overly complex patters. 
   While the invention is shown in only one of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit and scope of the invention.