Abstract: This invention provides a vehicle cruise control system which, during recognition of a shape of a road extending in a frontward direction of host vehicle, can calculate the road shape rapidly and accurately from a positional relationship with respect to the host vehicle. The system includes at least: a position change detector that detects, from information on the road existing in the frontward direction of the vehicle, a horizontal distance from a line segment orthogonal to a traveling direction vector of the vehicle, to a centerline of the road, the detection being conducted at a plurality of measuring points in an extending direction of the traveling direction vector; a road shape recognizer that identifies the shape of the road from data relating to linearity of changes in each of the horizontal distances, the linearity data being obtained by the position change detector; and a cruise controller that controls traveling of the vehicle according to results of the identification by the road shape recognizer.

Abstract: This invention provides a vehicle cruise control system which, during recognition of a shape of a road extending in a frontward direction of host vehicle, can calculate the road shape rapidly and accurately from a positional relationship with respect to the host vehicle. The system includes at least: a position change detector that detects, from information on the road existing in the frontward direction of the vehicle, a horizontal distance from a line segment orthogonal to a traveling direction vector of the vehicle, to a centerline of the road, the detection being conducted at a plurality of measuring points in an extending direction of the traveling direction vector; a road shape recognizer that identifies the shape of the road from data relating to linearity of changes in each of the horizontal distances, the linearity data being obtained by the position change detector; and a cruise controller that controls traveling of the vehicle according to results of the identification by the road shape recognizer.

Abstract: A device and method are provided for driving an ultrasonic motor. The motor's initial start drive frequency is set higher than the resonant frequency of the motor and an initial target drive frequency is set lower than the resonant frequency. A drive signal is then applied to a piezoelectric element on the stator in order to rotate the rotor. The frequency of the drive signals is then swept from the start frequency to the target frequency. Abnormal vibrations of the rotor that occur during sweeping of the drive frequency are detected by a monitor electrode mounted on the stator. Upon the detection of an abnormal vibration, the target frequency is reset to equal the drive frequency at which the abnormal vibration was detected. The drive frequency is then reset to a reset start frequency that is higher than the reset target frequency. Thereafter, the drive frequency sweeping step is repeated. This provides a high output from the motor without generating noise.

Abstract: An improved driving circuit for an ultrasonic motor is disclosed. The driving circuit includes an oscillator that outputs an oscillating signal. A driving means receives the oscillation and an input control signal and outputs a drive signal that drives the ultrasonic motor. The driving means is arranged to gradually alter the driving signal in response to the input signal by modifying the oscillation signal and amplifying the modified signal. In this manner the rotational speed of the ultrasonic motor is gradually change in response to the operational condition changes ordered by the input device.

Abstract: A method for driving a supersonic motor includes the steps of driving the supersonic motor by supplying a driving voltage of greater frequency than a resonant frequency (point) to a driving piezoelectric electric element. The driving frequency is decreased when a wave form distortion is not generated in an output signal of an oscillation detection piezoelectric element provided in an elastic body. The driving frequency is increased when a wave form distortion is generated in the output signal of the oscillation detection piezoelectric element.

Abstract: A serum-free medium for cultivating a human monoclonal antibody-producing human/human hybridoma, said medium comprising a serum-free complete medium and at least 10.sup.-12 M but not more than 10.sup.-6 M of retinoic acid or its salt.