| 摘要 |
FIELD: transport. SUBSTANCE: pulse-frequency modulation is used to control brakes and clutch 10 operating under action of liquid pressure in drives 22 controlled by electromagnetic valves 28. Short duration pulses for all duty factors are generated in case of provision of feedback with electromagnetic valve 28 or drive 22. In one control circuit electromagnetic system 30 switches on flip-flop which supplies current to solenoid. Movement of solenoid sets up counter-emf which acts onto magnetic flux in solenoid, or current is recorded and is used as feedback signal to switch off flip-flop and, consequently, cut off current immediately after operation of valve 28. In other control circuit computer controlled system 30' puts out command for definite pulse duration. Drive position or pressure in drive is observed to put out feedback signal to computer. If no signal is received, pulse duration in following command is increased until sufficient duration is found. If drive operation value exceeds threshold value, duration of pulse in following command for pulse generation is decreased. Pulse duration modulation can be improved by the same methods to bring pulse duration to minimum at the lowest duty factors, simultaneously providing guaranteed operation. EFFECT: enhanced reliability of torque transmission. 3 dwg |
