Roll sensor system for a vehicle
First Claim
1. A land vehicle roll sensor system for detecting a vehicle roll condition and for activating a safety system in response thereto, comprising:
- an angular rate sensor sensitive around at least one roll axis of the vehicle, said angular rate sensor producing an angular rate output signal representative of an angular rate around said at least one roll axis;
an integrator, including an input and an output, said integrator receiving said angular rate output signal at said integrator input and integrating said angular rate output over time to produce an integrated angle;
a first incline sensor sensitive along at least one incline axis perpendicular to said at least one roll axis of the land vehicle, said at least one incline axis being one of the X-axis and the Y-axis of the land vehicle, said first incline sensor producing a first incline sensor output;
a second incline sensor, said second incline sensor being sensitive to the Z-axis of the land vehicle, said second incline sensor producing a second incline sensor output;
a processor connected to receive said integrated angle, said angular rate output signal, said first incline sensor output and said second incline sensor output and to calculate a current incline angle from said first and said second incline sensor outputs, said processor comparing said current incline angle with said integrated angle and adjusting said integrated angle to compensate for drift if the difference between said current incline angle and said integrated angle is greater than a predetermined amount, said processor additionally generating a safety system trigger signal if after the comparison, at least said integrated angle correlates to a desired safety system activation event; and
at least one safety system deployment control unit operatively connected to receive said trigger signal from said processor and to activate the safety system based upon receipt of a trigger signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A roll sensor system for a land vehicle is provided to determine when a vehicle roll condition has occurred and to trigger a safety system in response to that determination. In certain embodiments, an angular rate sensor is used to obtain an angular rate and, from the angular rate, an angle relative to the roll axis of the land vehicle. If the angular rate and the angle correspond to a safety system activation event, the roll sensor system will provide a trigger signal to the safety system. In some embodiments, the system includes an incline sensor(s) to aid in detecting and compensating for drift in the output of the angular rate sensor. In other embodiments the output of an angular rate sensor is used to validate the output of the incline sensor to aid in determining whether a vehicle safety system trigger event has occurred.
19 Citations
27 Claims
-
1. A land vehicle roll sensor system for detecting a vehicle roll condition and for activating a safety system in response thereto, comprising:
-
an angular rate sensor sensitive around at least one roll axis of the vehicle, said angular rate sensor producing an angular rate output signal representative of an angular rate around said at least one roll axis;
an integrator, including an input and an output, said integrator receiving said angular rate output signal at said integrator input and integrating said angular rate output over time to produce an integrated angle;
a first incline sensor sensitive along at least one incline axis perpendicular to said at least one roll axis of the land vehicle, said at least one incline axis being one of the X-axis and the Y-axis of the land vehicle, said first incline sensor producing a first incline sensor output;
a second incline sensor, said second incline sensor being sensitive to the Z-axis of the land vehicle, said second incline sensor producing a second incline sensor output;
a processor connected to receive said integrated angle, said angular rate output signal, said first incline sensor output and said second incline sensor output and to calculate a current incline angle from said first and said second incline sensor outputs, said processor comparing said current incline angle with said integrated angle and adjusting said integrated angle to compensate for drift if the difference between said current incline angle and said integrated angle is greater than a predetermined amount, said processor additionally generating a safety system trigger signal if after the comparison, at least said integrated angle correlates to a desired safety system activation event; and
at least one safety system deployment control unit operatively connected to receive said trigger signal from said processor and to activate the safety system based upon receipt of a trigger signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 25)
-
-
8. A method of correcting drift in the output of an angular rate sensor used in a vehicle roll sensor system for detecting a land vehicle roll condition, for activating a safety system in response thereto, comprising:
-
(a) providing an angular rate sensor sensitive to motion around at least one roll axis of the land vehicle;
(b) providing a first incline sensor sensitive along at least one incline axis, said incline axis perpendicular to said at least one roll axis of the land vehicle (c) providing a second incline sensor sensitive to the Z-axis of the land vehicle;
(d) obtaining an output signal from the angular rate sensor representative of the angular rate of change around said roll axis;
(e) integrating said output signal representative of said angular rate over time to obtain an output signal representative of angular rate sensor angle;
(f) obtaining from said first and second incline sensors a signal representative of instantaneous tilt along said at least one incline axis;
(g) comparing said angular rate sensor angle to said instantaneous tilt angle to obtain a difference value;
(h) adjusting said angular rate sensor angle by at least a portion of said difference value to compensate for drift;
(i) determining if at least said drift compensated angular rate sensor angle corresponds to a safety system trigger event; and
(j) generating a safety system trigger signal if it is determined in said determining step that a safety system trigger event has occurred. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 22, 24, 26, 27)
-
-
16. A vehicle roll sensor system for detecting a land vehicle roll condition and for activating a safety system in response thereto, comprising:
-
an angular rate sensor aligned to be sensitive around at least the X-roll axis of the land vehicle, said angular rate sensor producing an angular rate sensor output signal, said angular rate sensor being prone to drift;
a first incline sensor sensitive along at least the Y-axis of the land vehicle, said incline sensor producing a first incline sensor output signal;
a second incline sensor sensitive to at least the Z-axis of the land vehicle, said incline sensor producing a second incline sensor output signal;
a processor connected to said angular rate sensor and to said first and second incline sensors, said processor receiving said angular rate sensor output signal and said first and second incline sensor output signals, wherein said processor processes said angular rate sensor output signal to obtain a signal representative of the angular rate of said angular rate sensor and an angular rate derived angle corresponding to said angular rate sensor output integrated over time;
wherein said processor additionally processes said first and second incline sensor signals to obtain a signal representative of a current incline angle along at least the Y-axis;
a comparator for periodically comparing the current incline angle with the angular rate sensor angle to obtain a difference angle value;
drift angle compensation circuitry to produce a vehicle roll angle by adjusting said angular rate sensor angle by said drift angle value, to compensate for said drift component of said angular rate sensor angle;
activation logic circuitry including comparison circuitry, said activation logic circuitry in communication with said drift angle compensation circuitry to receive at least said vehicle roll angle, wherein said activation logic circuitry activates the safety system if at least said vehicle roll angle is greater than a threshold roll angle value.
-
-
21. A land vehicle roll sensor system for detecting a vehicle roll condition and for activating a safety system in response thereto, comprising:
-
an angular rate sensor sensitive along at least one roll axis of the vehicle, said angular rate sensor producing an output signal representative of an agular rate around said at least one roll axis;
an integrator, including an input and an output, said integrator receiving said angular rate output at said integrator input and integrating said annular rate output over time to produce an angle output;
an incline sensor, including an input and an output, said incline sensor receiving said angle output at said incline sensor input and adjusting said angle output to produce a corrected angle output;
a processor connected to receive said corrected angle and said angular rate and to correlate said angular rate signal and said angle to determine if a safety system activation event has occurred, said processor generating a safety system trigger signal is said determined angular rate output and said determined angle output correlate to a desired safety system activation event;
at least one safety system deployment control unit operatively connected to receive said trigger signal from said processor and to activate the safety system based upon receipt of a trigger signal.
-
-
23. A vehicle roll sensor system for detecting a land vehicle roll condition and for activating a safety system in response thereto, comprising:
-
an angular rate sensor aligned to be sensitive around at least one roll axis of the land vehicle, said angular rate sensor producing an angular rate sensor output signal, said angular rate sensor output signal being prone to drift;
an incline sensor aligned to be sensitive along at least an axis perpendicular to said at least one roll axis, said incline sensor producing an incline sensor output signal;
a processor connected to said angular rate sensor and to said incline sensor, said processor receiving said angular rate sensor output signal and said incline sensor output signal, wherein said processor processes said angular rate sensor output signal to obtain a signal representative of the angular rate of said angular rate sensor and an angular rate derived angle corresponding to said angular rate sensor output integrated over time, said processor additionally processes said incline sensor signal to obtain a signal representative of the angle of incline along the at least one incline axis;
activation logic circuitry including comparison circuitry, said activation logic circuitry in communication with said drift angle compensation circuitry to receive at least said vehicle roll angle, wherein said activation logic circuitry activates the safety system if said angular rate sensor output and vehicle roll angle correlate to a desired safety system activation event;
.wherein said processor calculates a drift-corrected angular rate sensor angle for a sample n according to;
Ac(n−
1)=[k*A(n−
1)]+[(1−
k)*Ai(n−
1)], wherein Ac(n−
1) is the drift-corrected angular rate sensor angle for sample n−
1, Ai(n−
1) is an incline sensor angle for sample n−
1, and k is a weighting factor between 0 and 1.
-
Specification