GB1364625A - Digital data processing system - Google Patents

Abstract

1364625 Digital computers; error detection DEFENCE SECRETARY OF STATE FOR 6 July 1971 [9 July 1970] 33326/70 Heading G4A Various errors in the control system of a computer controlled plant (e.g. one or more gas turbines in an aircraft) are corrected by means of an interchangeable apparatus. The apparatus.-Two gas turbines 114, 214 are controlled by digital computers 100, 200 connected thereto by input/output units 107, 207 (including multiplexers 108, 208) and transducers 112, 118, 212, 218. The system is notionally divided into an upper and lower channel (divided by line o) but the various components of the channels are interconnected as shown and control does not necessarily flow along the respective channel, e.g. transducers 118 are controlled via l/o unit 207. The transducers (actuators or sensors) are generally analogue and A/D and D/A converters are provided in units 107, 207. Two pilot's throttle levels 114, 214 are provided. Fault response units 126A, 226A break the power lines to the respective computers 100, on detection of certain faults. When one computer is thus disconnected the other one is informed and activates a standby program for the other engine so that this computer controls both engines. The faults which may be detected include error in the fault units, failure of communication between the computer and its engine, fault in a transducer, or faults in one computer reading the connection/non-connection of the other computer and they are detected by diagnostic programs using check calculations. The response to the first two faults is described (Figs. 2 and 3, not shown). In another embodiment (Fig. 4, not shown), four computers normally control four respective engines and a similar fault correction system is described. A detailed computer program, the same for each computer 100, 200, is described (Figs. 5 and 16 to 23, not shown). Means are provided for preventing a computer being disconnected for transient faults. In a modification, computer 100 normally controls both engines while computer 200 only operates one section of its program and in another modification two computers control one engine. The disclosure is the same as that of divided out Specification 1,364,626.