Patent GB-830686-A (GB)
Title: Tactical control training apparatus
Inventor: CUTLER ALBERT ERNEST
IPC: F41G9/00
Filed: 1956-03-29
Abstract: 830,686. Warfare teaching. COMMUNICATIONS (PATENTS) Ltd. March 29, 1956, No. 9825/56. Class 119 [Also in Groups XXXIII, XXXVI and XL(c)] Apparatus for training a pupil to control the movement of a first steerable object with respect to a second moving and steerable object comprise means serving to make available to the pupil an indication of the assumed instantaneous position of the second object with respect to the first object in order to present to the pupil a control problem which is relevant to the relative movement of these objects, simulation control means in respect of the first object whereby a pupil can control the assumed movement of this object to enable a solution of the problem to be sought, and means whereby the assumed movement of the second object is subject to perturbance as a result of the operation of said control means. The invention is described as applied to simulating an air interception exercise in which a fighter aircraft is manoeuvred to close with an enemy bomber, the perturbance comprising alterations in the bomber flight to evade the fighter but it is also applicable to simulating other tactical problems such as a bomber avoiding a fighter, a bomber attacking a ship, a craft attacking a submarine, controlling a radar, search light or guided weapon, training tank crews or maintaining an aircraft in its correct position in a flight formation. In the embodiment described the indication of the bomber position is provided by a simulated radar display but other forms may be used such as a simulated echo sounding display (for submarine detection problems), a visual display projected on a screen or a model of a craft being attacked. As shown in Fig. 1 the fighter is represented by a flight simulator 3 equipped with a simulated radar display and controlled by the pupil and the bomber is represented by a digital or analogue computer 4 into which the instructor sets the initial altitude, heading and airspeed of the bomber; alternatively the computer 4 is controlled by punched tape or a magnetic drum store in accordance with a predetermined flight programme. The bomber co-ordinates are computed in a known manner in computer 4 and fed together with the bomber heading to the simulator 3 which computes in a known manner the range R, altitude hr and elevation 6 of the bomber relative to the fighter, displays the relative position of the bomber on a P.P.I. display to which signals representing noise and clutter may also be applied, and feeds the quantities R, hr, #. bomber heading and fighter heading in the form of shaft rotations to a control unit 5 which generates D.C. perturbance signals Pv, PA and P# where:- # being the relative heading of the two craft. These D.C. signals modulate respective carriers from a generator 6 which are then applied to a recorder 7 and to the bomber computer 4 to modify the simulated air speed, pitch and altitude and heading respectively of the bomber in order to evade the fighter. The root mean square of the deviations in the bomber course may also be recorded. As shown in Fig. 2 the hr input shaft controls a potentiometer 28 producing a D.C. voltage proportional to hr and the R input shaft controls potentiometers 14, 15 and 16 producing D.C. voltages proportional to R, 1/R and -R, the -R voltage being applied to a potentiometer 29 which is controlled by the # input shaft to produce a voltage -R sin # and the 1/R voltage being applied to a potentiometer 42 controlled by the difference between the bomber and fighter headings. The D.C. signal Pv is produced by combining in amplifier 19 the voltage 1/R from potentiometer 12 and a voltage R produced by differentiating the voltage R from potentiometer 11 by a C.R. network 21, 24. The D.C. signal PA is produced by combining the voltages hr and -R sin # from potentiometers 28, 29 to give a resultant vertical error signal (hr -R sin #), deriving the reciprocal of this resultant by applying said resultant to control the gain of the feedback element 33 of a feedback amplifier 34, integrating said reciprocal in a feedback amplifier 37-38 and combining said reciprocal with the integral in an amplifier 40. The D.C. signal P# is produced by integrating the voltage 1/R# from potentiometer 42 in a feedback amplifier 47-49 and combining the input to and output from said amplifier 51. The carriers to be modulated by the D.C. signal are applied to amplifiers 19, 40 and 51 from a generator 6. In a modification the signal P# is derived from a voltage proportional to 1/# by energizing potentiometer 42 with a voltage of constant amplitude; additional perturbance signals related to the angular or linear acceleration of the fighter and to its rate of climb, dive, roll and pitch may be included. The bomber computer 4 should include means for limiting its perturbances in accordance with established performance characteristics.