Abstract: An ultrasonic measuring system detecting state informations of a vehicle other than a vehicle speed. An ultrasonic transducer TR1 directly detects the vehicle speed. A second ultrasonic transducer and a third ultrasonic transducer are disposed respectively in front of and at a back of a rotational center of the vehicle and separated from each other at a predetermined distance. They respectively transmit ultrasonic waves at right angles to the running direction of the vehicle and respectively at second and third predefined down-angles relative to the road. A two-dimensional speed of the vehicle can be measured on the basis of the speeds obtained by the transducers TR2 and TR3.

Abstract: An ultrasonic measuring system for a vehicle is composed of first and second ultrasonic transducing assemblies TR1 and TR2. Each transducing assembly TR1, TR2 has three ultrasonic transducers TR11, TR12, TR13, TR21, TR22, TR23 which are separated from each other at an angle of 120 degrees in a horizontal plane about axis disposed at a front and a rear of the vehicle, respectively. Each transducer transmits ultrasonic waves to a road surface at a predefined down-angle relative to the road surface and receives reflected waves from the road surface. Each of the transducers TR21, TR22, TR23 transmits ultrasonic waves to the road surface and receiving reflected waves from the road surface in an opposite direction to a corresponding one of the transducers TR11, TR12, TR13.

Abstract: There are disclosed an apparatus and a method for searching for the optimum route to be followed by a vehicle. The apparatus comprises a memory storing road maps, a keyboard having keys, and a microcomputer. The driver of the vehicle specifies a starting point and a destination in a network of roads displayed on a color CRT. Then, the microcomputer searches the network for a route which connects the starting point to the destination at the shortest distance.