Abstract: Estimators of a vehicle's position and attitude with respect to the earth are generated continuously by integrating the outputs of translational and rotational accelerometers that are attached to the vehicle. These estimators are corrected by comparing them to corresponding reference dynamic variables measured independently by instruments onboard the vehicle. The estimators are modified by slowly responding servo loops to equal their corresponding reference variables. Differences between certain of the estimators and their corresponding reference dynamic variables are used in generating feedback signals for correcting other of the estimators. By combining various of the estimators, system outputs representing sideslip angle and change in cross-track velocity can be generated.

Abstract: A programmable sound synthesizer, controlled by a microprocessor, can be fabricated according to the present invention to provide arbitrary programmability with respect to the waveform of an audible tone, frequency, amplitude, envelope shape of the wave train, including attack, sustain and the decay intervals of the envelope, rest or space intervals between notes as well as arbitrary selection of the note within an ordered sequence. A plurality of binary numbers, which in sequence are indicative of the waveform of the tone to be generated, can be read from a memory at a rate which defines the frequency of the waveform. The memory is read by an address generator whose repetition rate is controlled by an integrater. The rate of integration is in turn controlled by a tone number which is programmed into an appropriate register coupled to the integrater. Envelope and amplitude information may also be programmed into corresponding registers.