US 9,438,154 B2 · Method and device for controlling a motor vehicle windscreen wiper motor

Abstract

Method of controlling a motor vehicle windscreen wiper motor, powered and controlled by pulse width modulation (PWM) with duty ratio (T) of determined value, in which the instantaneous fundamental period of the modulated pulses is switched successively between at least two discrete period values (T1, T2), the duty ratio (T) of the pulses (PWM) being substantially established at a determined value for at least one determined duration (Tc) of switching of the modulated pulses. Application to the reduction of the EMC noise level in the radio frequency bands to be protected.

Claims15

Dependent claims

A method for controlling a windshield wiper motor of an automobile vehicle, powered and controlled in pulse-width modulation mode with a duty cycle of a given value, comprising:

successively switching an instantaneous fundamental period of the modulated pulses between at least two discrete period values, the duty cycle of the pulses being substantially established at the given value, for at least one given switching period of the modulated pulses,
wherein, for two successive instantaneous fundamental periods and corresponding two successive instantaneous fundamental frequencies of said modulated pulses, a maximum value of frequency bounding the frequency jump separating the two successive instantaneous fundamental frequencies is such that harmonic frequencies of the two successive instantaneous fundamental frequencies are distinct and separated by a band width greater than a value of measurement resolution frequencies band of electromagnetic noise within a given band of frequencies to be protected.

A method for controlling a windshield wiper motor of an automobile vehicle, powered and controlled in pulse-width modulation mode with a duty cycle of given value, comprising:

successively switching the instantaneous fundamental period of the modulated pulses between at least two discrete period values, the duty cycle of the pulses being substantially established at a given value, for at least one given switching period of the modulated pulses,
wherein for an instantaneous fundamental period and a corresponding instantaneous fundamental frequency of said modulated pulses, said instantaneous fundamental frequency is chosen so as to minimize the level of electromagnetic noise generated by the harmonic lines of said instantaneous fundamental frequency within a band of frequencies to be protected of given value, and
wherein two successive instantaneous fundamental frequencies of the modulation pulses of two successive switching periods are separated by a frequency jump included between a minimum value and a maximum value of frequency, said minimum and maximum values of frequency being a function of the band of frequencies to be protected.

Dependencies are inferred from the claim text.

Method and device for controlling a motor vehicle windscreen wiper motor

Life of this patent

Method and device for controlling a motor vehicle windscreen wiper motor

Life of this patent

Abstract

Claims15