DE2521982B2 - Circuit arrangement for the input of externally obtained path and time base pulses into a clock-controlled evaluation circuit - Google Patents

Description

15th

20th

The invention relates to a circuit arrangement for inputting data obtained externally from a vehicle originating path pulses and time base pulses in a clock-controlled evaluation circuit for determination the path and speed of the vehicle.

In the automatic control of vehicles, it is necessary that the control center of the Vehicles receives measured values from which they can determine the speed and the distance covered can determine the location on a given route for the individual vehicles from this. To this Purpose evaluation circuits are provided that work in time with the control center and which the Measurement data are supplied.

Path impulses can, for. B. be tapped on a wheel of the vehicle or by Doppler radar can be obtained.

A device for determining the speed at which time base pulses have a certain measuring time mark and the number of travel impulses within this measuring time as a measure of the speed of the Vehicle is determined is known from GB-PS 10 53 444. The synchronization performed here causes path pulses and time base pulses to enter the evaluation circuit at the same time. Be there the time base pulses are aligned with the distance pulses. This solution can be used as long as the Evaluation circuit does not use its own working cycle and so adapt to the cycle of the path pulses can.

To secure the driving operation, it is common to duplicate important assemblies or entire devices. A subsequent comparison of the output signals of these modules or devices can lead to processing errors be recognized. Since larger control units, e.g. B. on the vehicles or in the control center located computers, usually clock-controlled, the input of non-clock-synchronous signals, z. B. Distance pulses or external time base pulses lead to errors. If z. B. a path pulse at a time where if a system with a double evaluation circuit still registers it, the input of the second system working in parallel due to inevitable small differences in the data the switching elements used must already be blocked. When comparing the results of the two subsystems an error is then detected in the evaluation circuit. Such errors solve unnecessary correction and Check routines and, if they occur frequently, lead to an interruption of operation.

In order to prevent such errors from occurring and to ensure reliable evaluation of path and time base pulses To ensure this, they must be adapted to the cycle of the evaluation circuit.

This is the object of the invention and is achieved in that a first Flip-flop circuit and a second flip-flop circuit is provided for inputting the time base pulses, and that the two flip-flop circuits do not transfer the path pulses or time base pulses until the next Clock pulse of the evaluation circuit as synchronized path pulses or synchronized time base pulses through the evaluation circuit.

The invention will now be explained with reference to figures. It shows

F i g. 1 the circuit arrangement according to the invention with an evaluation circuit,

F i g. 2 timing diagrams in the circuit arrangement according to FIG. 1 occurring pulse trains,

3 shows the use of the circuit arrangement according to the invention in a duplicated evaluation system.

The F i g. 1 shows the circuit arrangement according to the invention, FIG. 2 the pulse sequences occurring there.

Path impulses b are given by a path sensor VKS to a first input D 1 of a flip-flop circuit FF1, time base pulses ei from a time base circuit Zß to a first input D 2 of a second flip-flop circuit FF2. Clock pulses a generated by a clock generator TG are applied to second inputs 71, Γ2 of the two flip-flop circuits FF1, FF2; the flip-flop circuits output at each clock pulse a is the lying at their inputs Dl and D 2 signal on, they buttons, therefore, the incoming paths pulses b and d from the time base pulses at the clock frequency. Changes in the pulses b and d are accordingly not emitted until the next clock pulse a at the outputs Q 1 and Q 2, respectively; thus synchronization of the incoming pulses b and d is achieved.

The synchronized path pulses c or time base pulses e reach an evaluation circuit DV, which is controlled by the clock pulses a.

The evaluation circuit DVhal has the task of determining the path S and the speed V of the vehicle from which these data originate from the synchronized path pulses c or time base pulses e.

The path is determined with the aid of a path pulse counter WIZ, which adds up all incoming path pulses c (input A 1). The meter reading is thus a measure of the location of the vehicle when the vehicle is on a planned route. To determine the speed, two monostable multivibrators MX and M2, a speed counter GZ and a memory SP are provided.

The synchronized time base pulses e mark the duration of a measuring time Mz from a positive edge to the next positive edge. The first multivibrator Ml triggers on these positive edges and emits a pulse / which is fed to the memory SP and the second multivibrator M2. The second multivibrator M 2 triggers on the falling edge of the pulse f and emits a further pulse g , which is sent to the counter GZ

is applied. The speed counter GZ also receives the distance pulses c.

At the end of a measuring time Mz , the pulse / the transfer (input O) of the count of the speed counter GZ in the memory SP. The speed counter GZ has added the path pulses c arriving during the measurement period Mz (input A 2); the counter reading is thus a measure of the speed V of the vehicle.

After the counter reading has been taken over into the memory SP , the pulse g resets the speed counter GZ (input R) and a new measuring time Λ / z begins.

Information about path 5 and speed V of the vehicle is thus available at any time at the memory output and at the output of the path pulse counter WIZ and can be called up, which is indicated by the arrows leading from DV.

In Fig. 3 shows an application of the circuit arrangement according to the invention. Two evaluation circuits DVi and DV2 receive the information relating to a vehicle from (not shown) also duplicate measuring points (distance sensors, time base circuits) and, as described above, obtain the distance s and the speed ν of the vehicle as values vi and si or independently of one another. ν2 and s2. The values vi and ν2 or si and s 2 can differ from one another within certain limits. All values s 1, s 2, ν 1, ν 2 are called up by two control centers 5Z1 and 5Z2, which are supplied by a common clock generator TG and in turn feed the clock pulses a to the evaluation circuits DVi and DV2. Both control centers check the received values vi, ν 2, si, 5 2 for their pairwise agreement. If the deviations are too great, it is assumed that a measuring device has failed and the vehicle is stopped; this is in FIG. 3 indicated by a line BR , the activation of which by one of the two control centers leads to the braking of the vehicle.

For this purpose 2 sheets of drawings

Claims (1)

Claim: Circuitry for entering vcn externally derived from a vehicle derived path pulses and time base pulses in a taktgestiiuerte evaluation circuit for determining distance and speed of the vehicle, characterized in that for input of the directional pulses (b) a first flip-flop circuit (FF X) and a second flip-flop circuit (FF2) is provided for inputting the time base pulses (d) , and that the two flip-flop circuits (FFi, FF2) do not transfer the path pulses (b) or time base pulses (d) until the next clock pulse (a) the evaluation circuit as synchronized path pulses (c) or synchronized time base pulses (e) to the evaluation:; switch through circuit fDV ^. 10