Реферат: 1305213 Antiskid braking systems SAABSCANIA AB 23 Oct 1970 [27 Oct 1969] 50457/70 Heading F2F In an antiskid braking system, the brake release signal controlling solenoid valves on each wheel is generated when wheel lock occurs by comparing vehicle speed, obtained by integrating the output of an accelerometer 9 with a wheel speed obtained from a tachogenerator on each wheel, the vehicle speed being "updated" by means of a predicted vehicle speed obtained from an angular speed transducer signal of a reference wheel 19, intermittently released during braking. The speed signals from wheel 19 are transmitted to an updating circuit 32 which compares the signals with the integrated accelerometer output. Each wheel has an electronic circuit 20 forming part of an electronic circuit 8 and the individual wheel speed is measured by means of tachogenerator 6, 7 which passes a signal a to a pulse shaper 22 the output b of which drives a frequency halving flip-flop 23. Pulses c from flipflop 23 control an analogue gate 24 which switches a signal e, from integrator 31 of block 21 measuring vehicle speed to an integrator 25. The integrator 25 output h is compared at 26 with a predetermined value therein, adjustable by means of a potentiometer 36, Fig. 3 (not shown), the output j of which comparator 26 passes to a memory flip-flop 27 transmitting an output signal to a drive circuit 29 for the solenoid. True vehicle speed is compared with the accelerometer output in a top follower circuit comprising integrator 31 and updating circuit 32. For measuring vehicle speed by wheel 19 when the latter is free running pulses a derived therefrom are fed to constant pulse generator 34 in circuit 21, which is common to wheels 1, 19, to produce pulses summed by a filter in an operational amplifier 35 and exhibiting a simple exponential delay so that the output corresponds to the tap speed of wheel 19 when free running and this is the true vehicle speed.