Back-up protection sensor for a vehicle
First Claim
1. A back-up protection sensor for a vehicle having working machinery, the sensor comprising:
- a substantially unidirectional antenna;
a Doppler detection unit operatively coupled to the antenna, the detection unit generating a radio frequency signal of from about 450 MHZ to about 1.5 GHZ, the antenna radiating the radio frequency signal and receiving a signal reflected from a conductive body in relative motion with respect to the sensor, the conductive body being within a predetermined detection region, the detection unit further generating a sensor output signal responsive to a difference in frequency between the radio frequency signal and the reflected signal; and
a vehicle interface processor, the interface processor being responsive to the sensor output signal and providing a control signal to disable the operation of the working machinery upon the sensing of the conductive body in relative motion with respect to the vehicle.
1 Assignment
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Accused Products
Abstract
A protection sensor for a lawn vehicle includes a substantially unidirectional antenna operatively coupled to a Doppler detection circuit. The Doppler detection circuit generates a radio frequency signal which is radiated by the antenna. When the radiated signal strikes an object, such as a person, animal or another moving lawn vehicle, within a predefined detection region of the sensor, the signal is reflected and received by the antenna. The Doppler detection circuit generates an output signal responsive to a difference in frequency between the radiated signal and the reflected signal, thereby indicating the presence of the moving object within the protection region of the sensor. The unidirectional antenna virtually eliminates false detections generated by the lawn vehicle, to which the sensor is mounted, or by the operator of the vehicle.
57 Citations
15 Claims
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1. A back-up protection sensor for a vehicle having working machinery, the sensor comprising:
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a substantially unidirectional antenna; a Doppler detection unit operatively coupled to the antenna, the detection unit generating a radio frequency signal of from about 450 MHZ to about 1.5 GHZ, the antenna radiating the radio frequency signal and receiving a signal reflected from a conductive body in relative motion with respect to the sensor, the conductive body being within a predetermined detection region, the detection unit further generating a sensor output signal responsive to a difference in frequency between the radio frequency signal and the reflected signal; and a vehicle interface processor, the interface processor being responsive to the sensor output signal and providing a control signal to disable the operation of the working machinery upon the sensing of the conductive body in relative motion with respect to the vehicle. - View Dependent Claims (2, 3, 4, 5)
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6. A back-up protection sensor for a vehicle having working machinery, the sensor comprising:
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a signal generator for generating a radio frequency signal of from about 450 MHZ to about 1.5 GHZ; a substantially unidirectional antenna operatively coupled to the signal generator, the antenna radiating the radio frequency signal and receiving reflections of the radio frequency signal off a conductive body, in relative motion with respect to the sensor, located within a predetermined detection region; a mixer, operatively coupled to the antenna and to the signal generator, the mixer combining at least a portion of the radio frequency signal from the generator with the reflected signal received from the antenna and generating an intermediate frequency signal including a sum component and a difference component corresponding to the addition and subtraction of the radio frequency signal and reflected signal respectively; a low pass filter operatively coupled to the mixer, the low pass filter substantially removing the sum component from the intermediate frequency signal, thereby producing a Doppler signal; a level detector operatively coupled to the low pass filter, the level detector comparing the Doppler signal with a predetermined reference signal and generating a sensor output signal indicative of the presence of the conductive body in relative motion with respect to the sensor, the conductive body being within the detection region of the sensor; and a vehicle interface processor, the interface processor being responsive to the sensor output signal and providing a control signal, said control signal disabling the working machinery when the conductive body in relative motion with respect to the sensor is detected. - View Dependent Claims (7)
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8. A method for detecting a conductive body near a vehicle having working machinery, the conductive body being in relative motion with respect to the vehicle, the method comprising the steps of:
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generating a radio frequency signal of from about 450 MHZ to about 1.5 GHZ; radiating the radio frequency signal in a substantially hemispherical radiation pattern; receiving a reflection of the radio frequency signal, the reflection being reflected from the conductive body in a predetermined detection region; combining at least a portion of the radio frequency signal with the received reflection and generating an intermediate frequency signal having at least a sum component and a difference component corresponding to the addition and subtraction of the radio frequency signal and the reflection respectively; filtering the intermediate frequency signal to substantially remove the sum component, thereby generating a Doppler signal; comparing the Doppler signal with a predetermined reference signal and generating a sensor output signal when the Doppler signal level exceeds the reference signal level, the sensor output signal indicating of the presence of the conductive body within the detection region of the sensor; and providing a control signal responsive to the sensor output signal, said control signal disabling the working machinery of the vehicle. - View Dependent Claims (9)
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10. A lawn vehicle, including a lawn cutting attachment in combination with a back-up protection sensor, the back-up protection sensor comprising:
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a signal generator for generating a radio frequency signal; a substantially unidirectional antenna operatively coupled to the signal generator, the antenna radiating the radio frequency signal and receiving reflections of the radio frequency signal off an object, in relative motion with respect to the sensor, located within a predetermined detection region; a mixer, operatively coupled to the antenna and to the signal generator, the mixer combining at least a portion of the radio frequency signal from the generator with the reflected signal received from the antenna and generating an intermediate frequency signal including a sum component and a difference component corresponding to the addition and subtraction of the radio frequency signal and reflected signal respectively; a low pass filter operatively coupled to the mixer, the low pass filter substantially removing the sum component from the intermediate frequency signal, thereby producing a Doppler signal; a level detector operatively coupled to the low pass filter, the level detector comparing the Doppler signal with a predetermined reference signal and generating a sensor output signal indicative of the presence of the object in relative motion with respect to the sensor, the object being within the detection region of the sensor; a driver warning system, the driver warning system being responsive to the sensor output signal and providing an indication that the object in relative motion with respect to the sensor has been detected; a vehicle interface processor, the interface processor being responsive to the sensor output signal and providing a control signal; and wherein the control signal disables the lawn cutting attachment when the object in relative motion with respect to the sensor is detected. - View Dependent Claims (11, 12, 13)
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14. A method for enhancing the safety of a lawn vehicle, the lawn vehicle including a lawn cutting attachment, the method comprising the steps of:
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generating a radio frequency signal; radiating the radio frequency signal in a substantially hemispherical radiation pattern; receiving a reflection of the radio frequency signal, the reflection being reflected from an object, in relative motion with respect to the lawn vehicle, in a predetermined detection region; combining at least a portion of the radio frequency signal with the received reflection and generating an intermediate frequency signal having at least a sum component and a difference component corresponding to the addition and subtraction of the radio frequency signal and the reflection respectively; filtering the intermediate frequency signal to substantially remove the sum component, thereby generating a Doppler signal; comparing the Doppler signal with a predetermined reference signal and generating a sensor output signal when the Doppler signal level exceeds the reference signal level; and providing a warning indication, the warning indication being responsive to the sensor output signal and indicating the presence of the object in relative motion with respect to the lawn vehicle within the detection region. - View Dependent Claims (15)
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Specification