Patent GB-1068524-A (GB)
Title: Improvements in or relating to vehicle training apparatus
Inventor: SHERIDAN GENE HAROLD
IPC: G06G7/70
Filed: 1964-03-24
Abstract: 1,068,524. Training drivers. GENERAL PRECISION Inc. March 24, 1964, No. 12415/64. Heading B7H. [Also in Division G4] A computing arrangement which simulates the response of a car to various control operations, for use in apparatus for training drivers comprising a trainees' station where the controls (e.g. accelerator pedal, gear lever &c.) are situated, includes a D.C. energized potentiometer R2 (Fig. 3) operated by the " accelerator" pedal for deriving a first potential which is applied via a scaling network R6-R10, including a number of signal paths of different resistance, one of which is selected by a switch S2 operated by the " gear lever," to an integrating network including a capacitor C2. The integrating network produces an output potential commensurate with the supposed speed of the car. As the accelerator pedal is depressed, corresponding to increasing engine speed, a greater voltage from the potentiometer R2, is applied to charge the capacitor C2. An integrating network R4-C1 is connected to the potentiometer R2 to simulate the lag normally experienced between operating the accelerator pedal and engine speed change. The setting of the gear lever, which controls the switch S2 and thus the resistance of the signal path determines the rate at which C2 charges. The charge acquired by the capacitor C2 thus simulates the acceleration of the car. The apparatus also enables automatic transmission to be simulated, and for this the various parts of the switch S3 are set in the opposite connections to those shown in Fig. 3. With the automatic transmission switch PRNDL set to " drive " (D), the voltage from R2 is fed via the resistor R22 to C2. The output from the capacitor is taken through the normally closed switch K-5 and an emitter follower circuit T1 to a meter arranged as a speedometer to give an indication of the car speed. Connected in parallel with the integrating capacitor C2 are a number of circuits arranged to discharge it when required so as to simulate the effects of braking and frictional forces. Friction, tyre and aerodynamic drag effects are simulated by the resistors R13-R14. If the gear is shifted to neutral and the engine switched off or the clutch disengaged, the related switch K2, S2 or S5 is opened and capacitor C2 discharges, simulating coasting to a stop. When the brake is applied switch S6 is closed, and as pressure is applied the resistance of the potentiometer R16 is reduced, so that C2 discharges at an increasing rate. S7 similarly simulates a parking brake. A circuit R20, C20, C21, relay coil K-SK and switch S-SK is used to simulate the effect of too sharply applying the brakes when travelling at speed. The switch S-SK is operated when the brake pedal is fully depressed, and a transient voltage is transmitted by the capacitors to operate the skid relay K-SK. A holding contact a keeps the relay on for as long as the switch S-SK is closed, so that the continued operation of the relay indicates a skid. Arrangements are incorporated for automatic transmission operation to indicate if the lever is set to park or reverse during conditions of appreciable forward speed, and to actuate a damage relay K-8 in such circumstances to open the power supplies for the simulated engine and prevent the engine being restarted. In order to indicate simulated engine stalling conditions, for example when the engine is idling with insufficient speed while the car is stationary, two switching circuits comprising transistorized Schmitt triggers 35, 36 are included. A voltage representing the engine speed is fed to these. If the speed falls below a set value the first trigger operates a warning light, while if it falls below a second value the second trigger operates a relay which disables the simulated engine power supplies. The input to these trigger circuits is such that improper clutch operation (operating switch S-5a and potentiometer R11) also causes engine stall to be indicated. The power supply and distribution system for the simulator (Fig. 2, not shown) include all the switches and warning indicators normally associated with an automobile. In using the training apparatus, the trainee sits at his controls and watches a film showing the road ahead. A track at the edge of the film (similar to a sound track) carries synchronized sets of coded pulses representing numbers, which are detected at the camera. The numbers refer to the action which the trainee should have taken at the relevant part of the film (such as turn right, dip headlights &c.). The coded number are fed to a decoder which applies a voltage to a line corresponding to the number. If the trainee takes the proper action, switches in the line are opened. If, however, the switches are not opened an error light is actuated by the voltage on the line.