Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P1/00—Details of instruments
  • G01P1/07—Indicating devices, e.g. for remote indication
  • G01P1/08—Arrangements of scales, pointers, lamps or acoustic indicators, e.g. in automobile speedometers

Definitions

• This invention relates to measurement of the speed and acceleration of locomotives, earth moving tractors, and other large vehicles. More particularly, the invention pertains to a novel measurement, determination and display of vehicle speed and acceleration, wherein digital tech ⁇ niques are utilized to produce an analog representation.
• the equipment disclosed and claimed in this applica ⁇ tion provides analog/digital indication of vehicular speed and acceleration utilizing both internal and ambient light sources.
• a vehicular speedometer operating from a wheel driven pulse generator which includes an essentially analog indication of speed, and acceleration/deceleration of the
• the display further incorporates a precise auxil ⁇ iary digital readout of the analog speed display and incor ⁇ porates a transflective liquid crystal display for all indications.
• the transflective characteristic provides enhanced viewing of the display in the presence of increased
• Digital techniques enabled by a microprocessor are utilized to measure speed through counting pulses from an end of axle, i.e axle driven pulse generator for accurate predetermined time intervals. Subsequent values of measured ,20 speed are stored during predetermined sampling periods for use in determining vehicular acceleration.
• a novel technique for speed -and acceleration mea ⁇ surement and display utilize at least two subsequent speed measurements averaged over a sample time somewhat larger
• the acceleration is then averaged by determining the difference in speed over the given overall time interval.
• the acceler ⁇ ation display utilizes a logical ergonometrically correct configuration, wherein rates of change of acceleration and
• deceleration are presented as vertical bars in increasing and/or decreasing sizes.
• deceleration is signified by vertical bars of decreasing size
• acceleration is signified by vertical bars of increasing size.
• a visual test initiated at any time by the vehicu ⁇ lar operator, provides a predetermined display of indica- tions of normal unit operation, and in the alternative, identifies malfunctions and establishes shutdown, providing the operator with beforehand knowledge that unit repair or alternate methods of speed measurement must be utilized. Calibration and adjustment of factors used in speed and acceleration measurement such as wheel diameter can also be user initiated. Access to adjustment and calibration is limited through the use of concealed switches actuated by an external permanent magnet.
• Figure 1 shows • a functional block diagram of the invention, particularly showing the signal/power flow paths for major system components.
• Figures 2 and 2a are plan views of the display portion of the invention, ' particularly showing the analog scale and pointer, with digital indication of the speed represented by the analog pointer, for operation wherein acceleration and/or deceleration is indicated by designated bars.
• Figure 3 is an operating flow chart of the speed indicator and display system of the invention, particularly showing the microprocessor function and including operation of the speed indicator measuring system, user initiated test/calibrate function and operator initiated diagnostic feature of the system.
• Figure 4 is a graphic and algebraic description of determining acceleration using concepts of the invention.
• Figure 5 is a perspective view of the speedometer indicator and electronic housing. A partial tear-away shows location of magnetically actuated test/adjust switches.
• Appendix "A” is a detailed instruction set, parti ⁇ u- larly keyed to acronyms of Figure 3, describing microproces ⁇ sor operation.
• a rotating input shaft or vehicular shaft 7 drives an end-of-axle pulse generator 6, of the type dis ⁇ closed and claimed in U.S. Patent 3,566,169.
• Electrical pulses at a repetition frequency proportional to the rota ⁇ tional speed of the input shaft 7 are processed in a filter 8, and transmitted to an appropriate input of a microprocessor 10 such as the Intel 80351.
• Power for the microprocessor is supplied by supply 4.
• the power supply 4 also supplies operating electrical power for the display driver 16, operating an electroluminescent portion 18 of the display 14.
• the microprocessor 10 supplies display information in a digital form to the liquid crystal display driver 12.
• the liquid crystal display driver further conditions the microprocessor output in order to provide indication (reference Figures 2 and 2a) of speed and acceleration on the display 14 in both analog and digital forms.
• indication reference Figures 2 and 2a
• the display combina- tion of the liquid crystal display 14 and electroluminescent panel 18 incorporate a transflective background.
• the transflective feature enhances viewing images on the display screen 14 using both ambient light and electroluminescent emissions.
• the display portion of display 14 is a configuration 30 (or 40) incorporating an analog-like indicator or pointer 32, which in operation traverses a circular path in radial alignment with the speed indicating circular scale 34.
• the electroluminescent display is contained in a housing 3, containing concealed magnetic control switches 20 and 22 (ref. Figure 5). These switches initiate micropro ⁇ cessor operation to adjust vehicle operating parameters and speedometer operational checks respectively (ref. "TEST ALL”, “INITIAL EDGE”, and “TEST EDGE” of Figure 3, page 3).
• Major speed divisions of the circular scale are arithmetically indicated in miles per hour, although kilome ⁇ ters per hour can be displayed as well. Typically, the circular scale contains 100 divisions.
• an additional, centrally located digital indication of the speed shown by the combination of the pointer 32 and scale 34 is shown at 44.
• the digital speed indication 44 incorporates speeds from zero to 99.99 miles per hour or, if desired, the kilometer per hour equivalent.
• the display 36 is an indication of negative acceleration, sometimes termed deceleration, in miles per hour per second (MPH/SEC) .
• deceleration in miles per hour per second
• ten vertical bars indicate deceleration in decreasin magnitudes from left to right.
• the extrem left hand bar indicates six miles per hour per second, whil the extreme right hand bar indicates deceleration of .2 miles per hour per second.
• Intermediate bars indicate decelerations of 4, 3, 2.5, 2.0, 1.5, 1.0, .75, and .5.
• an acceleration pattern 41 having a indication of acceleration by bars 42.
• the phantom or dashed indication of the location of acceleration bars 45 are typically 1.0 miles per hour per second, with a maximum acceleration bar at the extreme right hand portion of the pattern, typically 5.5 miles per hour per second.
• acceleration and deceleration values will need to be adjusted in order to accommodate vehicles of varying size and power.
• the embodi ⁇ ment disclosed reflects values found appropriate for diesel electric locomotives hauling "typical" freight trains of 100 cars.
• the method of determining acceleration as described in detail involves utilization of two successive values of speed.
• a timer incorporated in the microproces ⁇ sor 10 measures two complete cycles 52 and 53 (ref. "CALC SPEED" of Figure 3, page 3) .
• the time of each measured cycle is recorded within the microprocessor for use in determining a first speed as indicated at 52.
• a complete cycle is determined by the zero of crossing the voltage 50 having a frequency as generated by the end-of-axle generator 6.
• a second speed 53 is determined through measuring the time required for two complete cycles of the pulse generated voltage 50, as shown at 56.
• Acceleration of the vehicle in the time required to go from the first speed 52 to the second speed 53 is deter- mined as shown at 57 (ref. "AD" of Figure 3, page 3). It should be noted that the overall determination of accel ⁇ eration includes a variable or incremental speed delta t, in this case delta t2 (55). A similar incremental time, delta tl (54), was utilized in determining speed 1 (52). Measure ⁇ ment or determination of vehicular acceleration proceeds within the microprocessor as shown at 57, wherein the acceleration computation is symbolically depicted. Measure- ment of acceleration in the manner disclosed herein provides essentially jitter free or stable values for acceleration, due to the inclusion of the interim time, i.e. delta t, between successive vehicular speed measurements (ref.
• FIG. 3C With further reference to Figure 3, continued internal microprocessor handling of the information provided by pulses generated within the end-of-axle generator 6 and processed in signal filter 8 proceed as shown, with addi ⁇ tional reference to appropriate locations indicated in the attached Figure 3, describing in some detail internal operation of the microprocessor 10.
• the program disclosed utilizes ASM51 assembly language in programming the Intel 80351 microprocessor/controller, and further incorporating peripheral input/output devices.
• a detailed instruction set coordinated with ,the flow chart of Figure 3 is attached as Appendix "A”.
• the analog/digital speedometer provides ' an operating feature comprising advances in the digital speedometer art in order assist operating personnel in handling and maintaining the particular vehicle containing the speedometer.
• These features include; a) operational checks of the speedometer system providing operators with clear indication of an failure (ref. "TEST ALL” of Figure 3); b) convenient calibration of the speedometer including restricted access means of changing speedometer constants such as overspee trip point and wheel size ; and vehicular overspeed detec ⁇ tion and alarm (ref. "TEST EDGE" of Figure 3).
• the security switch located at the right rear portion of the indicator cabinet is enabled, essentially bringing the microprocessor program to the "INITIAL-EDGE" portion as shown on Figure 3.
• Magnetic actuation of the right-hand concealed hall effect switch 22 moves the program to Figure 3, page 6, at "SIZE", where at "WAIT 1", it is necessary to actuate the concealed mode switch 20 within a 30 second period.
• indication of the previously stored wheel diameter is obtained, having its left-most digit in a flashing mode indicating that subsequent actuation with the adjust or left-hand concealed switch 20 , will change the flashing digit.
• the versatility of the disclosed speedometer system allows adjustment to a relatively high rate of input signal pulses, thereby accommodating outputs of certain radio frequency doppler radar speed detectors.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Instrument Panels (AREA)
• Indicating Measured Values (AREA)
• Lighting Device Outwards From Vehicle And Optical Signal (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25204935

Family Applications (1)

Country Status (6)

Cited By (2)

Families Citing this family (2)

Citations (7)

• 1986
  • 1986-09-30 CH CH391086A patent/CH672683A5/fr not_active IP Right Cessation
  • 1986-10-17 WO PCT/US1986/002194 patent/WO1987003978A1/en unknown
  • 1986-10-17 AU AU64798/86A patent/AU6479886A/en not_active Abandoned
  • 1986-10-17 EP EP19860906636 patent/EP0263829A1/en not_active Withdrawn
  • 1986-11-27 GR GR862813A patent/GR862813B/el unknown
  • 1986-12-18 CN CN198686108239A patent/CN86108239A/zh active Pending

Patent Citations (7)

Also Published As

Similar Documents

Legal Events