Abstract: In an apparatus and method for estimating a stability factor of combustions in a vehicular internal combustion engine, a engine revolution synchronized filter processing is carried out for a signal derived in synchronization with the engine revolutions and, thereafter, a time synchronized filter processing is carried out to extract the frequency component correlated to the engine combustion stability factor. Noise components synchronized with the engine revolutions, based on a revolution speed sensor working accuracy error, and based on tire (road) wheel revolution (rotation) first-order vibration frequency are eliminated. In addition, a resonance frequency component in a vehicular drive train is extracted as a frequency component correlated to the combustion stability factor.

Abstract: A system and method for controlling an induction motor which basically achieve reductions in a steady state loss and in a transient loss of the induction motor such as a stepwise input of a torque instruction value T.sub.e *. Basically, a steady-state loss minimization magnetic flux calculating section calculates a secondary (rotor) magnetic flux .phi..sub.r * which minimizes the steady-state loss of the induction motor in response to a torque instruction value. A target magnetic flux .phi..sub.r and a differentiation of the target magnetic flux d.phi..sub.r /dt are thereafter calculated using a low pass filter transfer function such as .phi..sub.r =.phi..sub.r * 1/(1+.tau..sub..phi..S)(, wherein .tau..sub..phi. denotes a time constant, and S denotes a Laplace operator). A target torque T.sub.m is calculates using a predetermined transfer function in response to the torque instruction value such as T.sub.m =T.sub.e *.1/(1+.tau..sub.T.S)(, wherein .tau..sub.T is a time constant for the target torque).

Abstract: A vehicle control apparatus comprises various sensors sensitive to vehicle operating parameters for producing signals having values sensed for the respective vehicle operating parameters. The vehicle control apparatus also comprises a transition detector. The transition detector includes a memory for storing threshold values specified for the respective vehicle operating parameters, and a comparator for comparing the sensed values with the respective threshold values in a predetermined sequence to sense a transition in one of the vehicle operating parameters when the value sensed for the one vehicle operating parameter is in a range defined by the threshold value specified for the one vehicle operating parameter. The transition detector is coupled to a control unit for controlling the automotive vehicle for the sensed transition.

Abstract: A digital speedometer includes a pulse counter, a timing pulse generator, an indicator register, a display, and a comparator for comparing the magnitude relationship between a counted value counted by the pulse counter and the memorized value of the indicator register, two counters in addition to the pulse counter, and a plurality of logic circuits. The comparator generates signals indicative of the magnitude relationship between the counted value and the memorized value. The two counters may output a first or second gate signal respectively to the AND gate connected to the indicator register, in response to the signals output from the comparator at a predetermined time cycle depending upon the gate time controlled by the timing pulse generator, in such a manner so as to renew the memorized value with the counted value only when the number of occurrences of the output of the first or second signals reaches a preset number thereof.