GB2214009A

GB2214009A - Emergency brake indicator

Info

Publication number: GB2214009A
Application number: GB8729607A
Authority: GB
Inventors: Jenn-Yih Lin
Original assignee: LIN JENN YIH
Current assignee: LIN JENN YIH
Priority date: 1987-12-18
Filing date: 1987-12-18
Publication date: 1989-08-23
Also published as: GB8729607D0

Abstract

A first store 31 stores a value representative of speed in a first unit of time, a second store 3 stores the speed value in second subsequent unit of time, and a comparator 7 compares the two values to detect deceleration beyond a predetermined level and actuate a warning device 9. An oscillator 1 produces pulses of 0.5 or 1 second width. During each pulse a counter 2 counts pulses generated from the vehicle drive transmission. At the end of each oscillator pulse the content of counter 2 is transferred to store 3 and the previous count in store 3 is transferred to store 31. Comparator 7 compares the count in store 31 with the output of an wider 6 which sums the count in store 3 with a reference value held in circuit 4 and representative of a predetermined deceleration. Resetting of counter 2 and the transfer of the count from store 3 to store 31 are controlled by delay circuits 5, 51 respectively. Circuits 4, 6, 7, 8, 9, 31 may be duplicated, (Figure 3), the circuits 4 holding different reference values so that the corresponding indicators 9 are operated at different deceleration values. <IMAGE>

Description

EMERGENCY BRAKE INDICATOR This invention relates to an emergency brake indicator, especially an indicator for a vehicle such as a car under circumstances of emergency braking to warn the driver of a following vehicle to take precautionary measures.

In recent years, as the living standards has been improved, motor cars have become universally available as a main form of transportation.

Tb meet the increase in the number of cars, motorways have been constructed. When travelling at high speed on a motorway, it is easy for a driver to be careless and it may be too late for the driver of the car behind to step on the brake when depending upon the brake indicating lamp of a car in front to provide a warning, because the purpose of a conventional brake indicating lamp is only to let the car behind know that the brake of the car in front is being applied. However, there are two situations for applying on the brake, during an emergency or when there is no emergency. In the case when there is an emergency, when the driver of the car behind begins to apply his brakes after noticing the brake lights of the car in front, it is very easy to cause a collision, or even the tragic situation of a serious chain accident.

This, invention provides an emergency warning indicator device so that when the emergency brake of a car is applied the cars behind will be properly warned to either apply the brake or get out of the way, resulting in a reduction in the number of accidents.

According to the present invention there is provided an emergency brake indicator conprising first means for storing a value representtive of speed in a first unit of time, second means for storing the speed value in a second subsequent unit of time and comparison means for comparing the two values wherein a decrease in output of the computer means beyond a predetermined level actuates a warning device.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a block diagram of an emergency brake indicator according to the present invention; Figure 2 is a circuit diagram of the indicator of Fig. 1; and Figure 3 is block diagram of another emergency brake indicator according to the present invention.

Referring specifically to Fig. 1, an emergency brake indicator of this invention comprises an oscillator 1, a counter 2, two parallel in/parallel out temporary stores 3 and 31, an establisher 4, two delays 5 and 51, an adder 6, a comparator 7, a controller 8, and an indicator 9.

Each time the gear or transmission shaft of the car rotates one revolution, one pulse is applied to counter 2 and adds a value one to the count of counter 2. The oscillator 1 is set to produce a pulse of 0.5 second (2Hz) or 1 second (lHz) duration, and after each established unit time is reached, the value in the counter is entered into the first temporary store 3.

After the predetermined unit time of the oscillator has elapsed, then the value measured by the counter during this unit time is applied to the temporary store 3. The delay 5 then effects a preset delay whereupon the counter 2 is cleared to zero. This process is immediately repeated so that signals representive of the rotational speed of the transmission gears are applied to the counter 2 and accurately counted.

Furthernore, after the pulse signal applied to the temporary store 3 appears at the output thereof, the pulse signal is applied to a second parallel in/parallel out temporary store 31 connected to the temporary store 3 which stores the input value of the last unit time. A rotational speed value obtained for the motor car gearing is inputted to establisher 4 and is pre-established as an initial value.

After another input value corresponding to the value of the rotational speed in the next subsequent unit time is applied to temporary store 3 the adder 6 adds the values of temporary store 3 and establisher 4. The count in the adder 6 and the last input value in the temporary store 31 are compared by comparator 7. If the value of the output of the adder 6 is smaller than that of the temporary store 31 it is indicative of the decreasing speed being larger than that of the established speed. The horn controller 81 and emergency brake indicating lamp controller 82 make the horn 91 emit a sound and lamp 92 emit flashing light as a warning to the cars behind. A pulse extender 83 established in controller 8 may control the operating time of the horn 91 and the lamp 92.

If the value in the adder 6 is larger than the value of temporary store 31, the controller 8 will not operate. The time delay of delay circuit 51 must be longer than the time for completion of the comparison operation mentioned above. After completing the comparison, the value of the first temporary store 3 is applied to the second temporary store 31 to be used for the next comparison operation. By using the abovementioned method, adders 6, comparators 7 and establishers 4 can be arranged as shown in Fig. 3 to control two sets of indicators. Each indicator set has its own controller 8 and indicator 9 and the preset value of the establisher 4 in each set is not the same.Depending upon different degrees of application of the brake, the indicator 9 of one or more sets will generate a warning signal so that the driver of the car following will be aware of the extent of emergency braking applied by the car in front and can take proper precautionary measures.

A more detailed circuit diagram is shown in Fig. 2 where the delay circuit 5 comprises a D-type flipflop Ul, a resistor R1 and a capacitor C1. When a pulse wave changes from low potential to high potential, output Q of the D-type flipflot Ul will be at high potential charging capacitor C1 which makes D-type flip-flot Ul reset and restores the output Q to high potential. The counter is cleared to zero position for restarting counting from the beginning.

A NOT GATE 51 is provided to effect a delay of half a cycle, whereupon the value of temporary store 3 is transferred into temporary store 31. Therefore, in the case of emergency braking, the operating time of the comparator 7 output is about half a cycle until the next comparison which automatically changes the comparator output to keep stability of no action. If there is a need to have a longer delay time, a pulse extender 83 is added for extension of the operating time.The establisher 4 may use an ON-OFF switch. When the ON-OFF switch is set at OFF, its value is one and when the switch is set at ON, its value is zero.

The purpose of the installation of a D-type flipflop U2 is for preventing the counter 2 from changing state whilst temporary store 3 reads the value of the counter 2. When the input changes from high potential to low potential, it may determine at this moment if oscillator 1 is also in a changing state. At this time, the counter 2 remains in an unchanging state, because the counter can only change state when the input signal changes from low potential to high potential.

In conclusion, because of the simple construction and practical functional effect of the indicator, the emergency brake indicator of this invention achieves the effect of an early warning indicator.

Claims

cIAI:

1. An emergency brake indicator comprising first means for storing a value representative of speed in a first unit of time, second means for storing the speed value in a second subsequent unit of time and comparison means for comparing the two values whereby a decrease in output of the caparison means beyond a predetermined level actuates a warning device.

2. An indicator as claimed in claim 1, wherein the second means is a store connected to one input of an adder and a device containing a preestablished value connected to another input of said adder, the comparison means being arranged to compare the output of the adder with the output value from the first storage means.

3. An indicator as claimed in claim 1 or 2, wherein the first means is another store and is connected to receive output from said store of the second means.

4. An indicator as claimed in any one of the preceding claims, including clock means arranged to clock the first and second stores at preset times.

5. An indicator as claimed in claim 4, including first delay means connected with the clock means, and a counter for producing signals representative of speed, whereby said delay means is arranged to delay the clock signal by a preset time whereupon the counter is cleared.

6. An indicator as claimed in claim 4, including second delay means connected to the clock means and said another store for delaying the output of said another store by a time which is longer than the time for completion of the comparison operation in the said comparator means.

7. An indicator as claimed in any one of the preceding claims, wherein the warning device comprises an audible device and/or a light flashing device.

8. An indicator as claimed in claim 7, including a pulse extender circuit connected between the output of the comparison means and the warning device for increasing the action time of the warning device.

9. An indicator as claimed in any one of the preceding claims, including a dual arrangement of first and second means for storing comparison means and warning device.

10. An indicator as claimed in any one of the preceding claims, wherein the emergency brake indicator is digitally operable.

11. An emergency brake indicator substantially as hereinbefore described, and as illustrated in, Figs. l and 2; or Fig. 3 of the accompanying drawings.