Abstract: The invention is directed to a method and apparatus for influencing the driving speed of a motor vehicle. The apparatus includes an electronic control unit which includes a microcomputer and a memory. In the control unit, a controller is implemented for the driving speed of the vehicle which is chargeable with an adapted proportional amplification and an integral amplification in dependence on selected and actual driving conditions of the vehicle. The driving modes of "accelerate", "decelerate" and "resume" are automatically carried out pursuant to the steps of the method. Smooth transitions between different speeds are obtained by operating the controller as a proportional controller during acceleration phases.

Abstract: An automotive engine forming part of a motor vehicle is controlled to avoid slipping or spinning of a driven wheel by controlling the maximum rate of change of fuel which can be supplied to the engine, for example, by limiting the speed of deflection of a throttle flap (6) driven by a servo motor (7). The deflection speed, limited for example by a voltage divider (14) can be controlled as a function of operating parameters of the engine or the vehicle, for example, vehicle speed (V.sub.F), engine speed (n.sub.M), engine loading or a percentage of engine loading, actual wheel slip, actual angle or deflection position of the throttle flap, and the like. Further, non-linearities between deflection of an operator actuated pedal, such as a gas pedal (1) and actual deflection of the control flap (6) can be compensated for, for example, in a difference forming circuit (9) providing an output error signal for the servo motor (7) or by software, e.g.

Abstract: To provide an inexpensive test apparatus for testing the performance of control computers in automotive vehicles, for example sufficiently simple to be affordable by gasoline service stations, small garages and the like, a shift register-memory combination unit is provided receiving the data in serial, preferably Pulse-Duration-Modulated (PDM), form, and a monostable flip-flop is connected to the shift register, connected to be SET by a flank, preferably the trailing flank, of the first bit of a data word, and having a timing period somewhat longer than the longest interval between sequential bits, the monostable flip-flop being connected to control the shift register to transfer data in the shift register to a memory section thereof for simultaneous display of the data in the various storage locations of the memory section of the shift register.

Abstract: To increase the resolution of digital words, for example eight-bit words, being supplied via a digital/analog (D/A) converter (2) to a closed control loop, the lowest-order bit (2a) is chopped with a duty cycle, that is, controlled pulse duration/pulse gap ratio, for accurate resolution of the entire word being transmitted. The D/A converter will provide an output of undulating or wavy form, which undulations or waves are averaged or integrated by a low-pass filter (5) or low-pass transmission characteristics of a controller (6) or the overall control loop (4-6-7-8-9-10-11-4) to which the analog signal is applied as a command signal.

Abstract: To allow for apparatus tolerances, aging of equipment, and changes in operation, for example due to changes in temperature, in a closed-loop servo system in which an operator-controlled fuel supply control element (1) provides, via a coupled command control transducer (2), a signal to control a positioning motor (8) which moves a fuel supply control element (9, 29) in accordance with deflection of the operator control panel, a logic and calculating element, in form of a microprocessor (3) is provided, included in the control loop.

Abstract: To sense proper operation of a servo control loop including a fuel control pedal (1) which operates a command control transducer (2), e.g. a potentiometer coupled thereto, to provide a command signal to a controller (3) which energizes an amplifier (4) operating a positioning motor (5) which, in turn, changes the position of a fuel control element (7, 207), the instantaneous position of which is fed back to the controller by a position control transducer (6), a signal processing and logic circuit (9, 13) is provided which has the actual fuel supply signal applied thereto. The actual fuel supply signal is evaluated with respect to predetermined limits, for example at a "rest" or OFF position of the fuel control element. This condition can be sensed, for example, based on operating data of the engine, e.g. when a brake light switch is operated, the engine operates above a certain speed, or the vehicle operates at a certain speed, or the like.

Abstract: In a free-wheeling vehicle drive system in which the free-wheeling function is cut in and cut out entirely in response to normal driving operation of acceleration and deceleration, at least the signal corresponding to engine acceleration, which may be provided by the accelerator pedal, is subjected to delay before it may set a flipflop establishing the free-wheeling function. The braking signal, which may conveniently be derived from the brake-light switch, can likewise be advantageously delayed in its resetting of the flipflop in order that brief touching of the brakes should not disable free-wheeling. A more refined system which cuts in free-wheeling only after acceleration of the engine followed by the establishment of an idling condition of the engine can be used without the necessity of providing an overrunning clutch, since the control of a normal clutch connecting or separating engine and drive train can provide free-wheeling.

Abstract: To permit use of a manual transmission with the advantage of positive drive and hence better fuel economy with a controlled clutch (14), for example under operator control (13) or gear selection control (2013), an engine fuel control positioning stage (11) is provided which receives, upon start of the vehicle and change of the transmission from neutral to first gear, an engine starting speed reference signal from an engine speed controller (19). The clutch, under operator or gear change control, has a disengagement path (15) which causes rapid disengagement of the clutch and a connection or reengagement path (16) which operates with time delay to cause gradual engagement of the clutch so that smooth start-up is insured. A suitable start-up speed is idle speed of the engine, or close thereto.

Abstract: To reduce disturbance and interference signals, and particularly recurring disturbance signals due to vibration or out-of-round conditions of rotating elements coupled to a speed transducer, a low-pass filter (11) is connected to the speed transducer and, in addition, a high-pass filter (12) which, however, is disconnected upon sensing that the speed of the wheel or of the vehicle is below a predetermined limit, or that the anti brake-lock system unit (13) has responded. Thus, disturbance signals, and particularly periodic disturbance signal which might cause oscillatory conditions to arise in the filter and transducer circuitry, are effectively suppressed.

Abstract: To provide an indication of the presence of a trailer connected to a vehicle, operating as a tractor, without any additional terminal or contact elements on a plug-socket connector between the electrical system of the tractor and the trailer connected thereto, a logic gate (11), preferably a NAND-element, is connected to the output line of the direction flasher circuit, or other suitable connecting line, to a low-resistance load on the trailer, for example the brake light (19a), position lights or the like, the resistance circuit element including a connection from the positive power supply through a resistor (12) having a value which is high with respect to that of the lamps on the trailer (19, 19a) so that, with the trailer disconnected, an effectively 1-signal will be applied to the logic circuit but, upon connection of a low-resistance lamp, that is, upon connection of a trailer socket, the signal at the logic gate will drop to a O-signal although the current through the lamp is insufficient to cause ligh

Abstract: The heat exchanger of the temperature control system for a vehicle passenger compartment exchanges heat with air entering the passenger compartment. The flow of heat-exchange medium through the heat exchanger is controllable for controlling passenger-compartment temperature. A servo comparator receives and compares a temperature command signal and a feedback signal and produces an error signal which operates an actuator which in turn actuates an adjuster for fluid flow through the heat exchanger. The command signal is derived from a command transducer whose setting is adjustable by a passenger. The feedback signal is derived from a passenger-compartment temperature sensor but additionally, in order to avoid system instability, is furthermore derived from a heat-exchanger temperature sensor. In particular, the feedback signal includes a component whose value is determined by the rate of change with respect to time of the temperature sensed by the heat-exchanger temperature sensor.

Abstract: To decode signals picked up in a horizontal and vertical coil on the vehicle induced by a buried a-c energized cable, in which the vertical position of the coil above the cable is determined, a null sensing circuit is coupled to the horizontal coil to sense when the signal induced therein passes through zero. The signal induced in the vertical coil is likewise sensed, but rather than sensing the null, the peak value is determined. This peak value induced in the vertical coil will occur some time after the signal in the horizontal coil has passed through null or zero, and the peak value in the vertical coil is compared with the rise in signal in the horizontal coil. When the two signals (peak and rising horizontal coil signals) are equal, the time between the equality and the null point of the horizontal signal is determined, and used as a control parameter to steer the vehicle so that this time will be effectively null or zero, at which time the vehicle will be centered over the guide cable.

Abstract: An apparatus to regulate the temperature of the interior of a motor vehicle, including a room air temperature sensor and a heating air temperature sensor, with the room air temperature sensor providing a substantially higher controlled variable change per unit of temperature change and wherein the sensor signals are summed by a controller. The heating air temperature sensor consists of two series-connected temperature sensors of which one is thermally insulated. The sensor control signal is taken from the junction between these two temperature sensors so as to provide dynamic coupling of the heating air temperature sensor to the room air temperature sensor. In this manner, the room air temperature is sensed precisely and relatively more rapidly so that an excessively large fluctuation of the actual temperature is avoided if the heating output of the heat exchanger varies between a high and a low value.

Abstract: A motor vehicle is equipped with a heater assembly in which hot coolant from the engine is circulated through a first heat exchanger, normally called heater. The vehicle is also equipped with a refrigerating unit, i.e., an air conditioner, which has a second heat exchanger, or cooler, located in front of or behind the heater. Two separate temperature sensors are provided. One of these senses the compartment temperature while the other is located directly adjacent to the heater and senses the temperature of the air leaving the heater. The responsivity of this latter sensor is made substantially lower than that of the compartment sensor, i.e., its signal change per unit temperature change is lower, resulting in differential weighting. A control unit is so constructed that when the compartment temperature rises, the heater, which is normally cycled on and off in a quasi-continuous fashion, is shut off. If the temperature rises further, the controller activates the refrigerator unit and the air is cooled.

Abstract: The time duration of output pulses from the transducer, including wave-shaping circuits, if used, is measured and compared with respect to predetermined time limits. Two sequential pulses are measured and stored. If both pulses are shorter than a predetermined time interval, no alarm signal is generated; if the first pulse is longer than a predetermined time interval and the second also longer than a predetermined time interval, an alarm signal generation circuit, otherwise activated by the second, longer signal, is inhibited (since acceleration or deceleration of the wheel is indicated); if, however, the time duration of the second sequential pulse is longer than a predetermined time interval, but the time duration of the preceding pulse is shorter than its time duration threshold value, the malfunction signal is not inhibited, indicative of malfunction, loose contacts, or the like.

Abstract: A heating system for a motor vehicle has temperature sensors for gauging the compartment temperature as well as for gauging the temperature of the effluent hot air. These sensors are connected in series, with the compartment sensor generating the more significant control signal. The flow of heating medium, for example engine water, is regulated by a valve under the control of a regulator which compares the sensors signals with a set-point value. The valve may be cyclically actuated by pulses of fixed frequency but having a width which depends on the results of the signal comparison.

Abstract: In the tractor vehicle a current measuring resistor is interposed in the line supplying current to a coupling connector terminal to which the antilock system of a trailer equipped with such a system is connected for its power supply. A resistor load is connected to this power supply line through a switch that is closed when no trailer is coupled but is held open when a trailer is coupled. The current through the current measuring resistor either flowing through the resistor load or through a normally functioning antilock system of a trailer causes operation of a threshold switch to energize the brake antilock system of the tractor vehicle.