Angular rate sensor
First Claim
1. A sensor mountable in a vehicle for providing a rotation signal responsive to rotation of said vehicle about a vehicle axis, and comprising:
- a rotor having a rotor axis about which it is free to rotate, said rotor axis being fixed relative to said vehicle and parallel to said vehicle axis; and
rotation sensing means responsive to rotation of said rotor about said rotor axis by providing said rotation signal.
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Accused Products
Abstract
A sensor for measuring yaw rate or roll rate of an automotive vehicle comprises a freely rotating inertial disk and an angular rate sensor responsive to the rotation of the inertial disk relative to a housing. In one embodiment the inertial disk presents an alternating magnetic field at its circumference. The rate and direction of rotation of the inertial disk relative to its housing is determined by three magnetic field sensors such as linear Hall Effect sensors responsive to the field presented by the inertial disk. In another embodiment electronic cameras measure movement of fiducial marks on the inertial disk. Air surrounds the inertial disk and air viscosity gradually brings rotation to a stop. For yaw rate measurement the disk axis is oriented vertically and the inertial disk is supported in the radial direction by low friction bearings such as ball bearings or magnetic bearings and in the axial direction by substantially frictionless bearings such as magnetic bearings. In certain embodiments two magnetic poles operate as both axial and radial bearings. For the purpose of sensing incipient or actual vehicle rollover, the axis of the inertial disk is oriented in the direction of the roll axis of the vehicle. The angle of a recent rotation and rate of rotation of the inertial disk relative to the housing indicate the angle through which the vehicle has recently rotated about its roll axis and the roll rate of the vehicle.
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Citations
36 Claims
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1. A sensor mountable in a vehicle for providing a rotation signal responsive to rotation of said vehicle about a vehicle axis, and comprising:
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a rotor having a rotor axis about which it is free to rotate, said rotor axis being fixed relative to said vehicle and parallel to said vehicle axis; and rotation sensing means responsive to rotation of said rotor about said rotor axis by providing said rotation signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An angular rate sensor comprising:
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a first member and a second member, said first member being rotatable relative to said second member, a visible element movable with said first member, a camera fixed with respect to said second member, said camera comprising an array of light sensing cells and a means for computing, and means for causing light from said visible element to form an image on said array of light sensing cells, and wherein; each said light sensing cell is responsive to said image by providing an intensity signal responsive to the amount of light being received, said means for computing is connected for receiving said intensity signals, and said means for computing is adapted for calculating the velocity of said image, whereby said velocity indicates the rate of rotation of said first member relative to said second member. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A vehicle rollover sensor comprising:
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a rotor having a rotor axis and mountable within a vehicle, said rotor being freely rotatable about the rotor axis, said rotor axis being fixed relative to the vehicle; and a detector for detecting rotation of said rotor about the rotor axis, said detector providing a detector signal indicative of rotation of said rotor relative to said detector, whereby a vehicle rollover condition may be determined based on the detector signal. - View Dependent Claims (24, 25, 26, 27)
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28. A sensor mountable in a vehicle and comprising:
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a rotor having a rotor axis about which it is inertially balanced and free to rotate, said rotor comprising an axle extending from said rotor concentrically with said axis, a bearing fixed relative to said vehicle for bearing said axle, and rotation sensing means responsive to rotation of said rotor about said rotor axis by providing a rotation signal indicating a rate of relative rotation, whereby said rotation signal indicates the rate of rotation of said vehicle about a vehicle axis oriented parallel to said rotor axis. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36)
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Specification