Patent ID: 6587074
Filing Date: 2003-07-01
Classification: B60K,G01S

Abstract:
A system for measuring a distance and a relative speed between objects using electromagnetic waves, the system comprising:an arrangement for transmitting the electromagnetic waves from a first object to provide transmitted signals; and an arrangement for receiving reflected electromagnetic waves from at least one second object; wherein: a transmitted frequency of the transmitted signals is modulated so that: the transmitted frequency is modulated approximately linearly from-a first modulation frequency value to a second modulation frequency value during a first time segment; the transmitted frequency is approximately constant during a second time segment; the transmitted frequency modulated approximately linearly from the second modulation frequency value to a third modulation frequency value during a third time segment; the transmitted frequency is approximately constant during a fourth time segment; and the first, second, third and fourth time segments recur repeatedly; a change being provided by changing at least one of the value of the first modulation frequency, the value of the second modulation frequency, the value of the third modulation frequency, the value of the fourth modulation frequency, the duration of the first time segment, the duration of the second time segment, the duration of the third time segment, and the duration of the fourth time segment; wherein: the change is a function of at least one of a measured distance and a measured relative speed between the first object and the second object; at least one of the duration of at least one of the first, second, third and fourth time segments and the at least one of the first, second and third modulation frequency values is constant for at least one predefined value range of the at least one of the measured distance and the measured relative speed; and at least one of the duration of at least one of the first, second, third and fourth time segments and the at least one of the first, second and third modulation frequency values are changed step-wisely using at least one step when the at least one predefined value range is exceeded.