AUTOMOTIVE CONTROL UNIT PROGRAMMED TO ESTIMATE ROAD SLOPE AND VEHICLE MASS, VEHICLE WITH SUCH A CONTROL UNIT AND CORRESPONDING PROGRAM PRODUCT
First Claim
1. Automotive electronic control unit (ECU) programmed to real-time estimate vehicle mass based on a vehicle acceleration signal from an accelerometer, a vehicle speed signal, and other signals representing a vehicle propulsive/resistive torque;
- wherein vehicle mass is estimated;
a1. when the vehicle is in motion,a2. compensating for accelerometric disturbances due to;
a21. vehicle dynamic pitch; and
a22. accelerometric components due to vehicle lateral dynamics; and
a3. based on a recursive least square algorithm with forgetting factor inputted with a compensated vehicle acceleration signal, anda4. at different low gears, to estimate vehicle mass and associated variance for each gear, anda5. based on vehicle mass estimations and corresponding variances for each gear, anda6. minimizing uncertainties on propulsive/resistive torque due to gear efficiency and rolling resistance.
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Accused Products
Abstract
Automotive electronic control unit programmed to realtime estimate either or both of vehicle mass and road slope, wherein; a. road slope, is estimated; a1. when vehicle is considered stopped based on an accelerometer signal indicative of vehicle acceleration, wherein the vehicle is considered stopped in the presence of substantially zero values of a speed signal indicative of vehicle speed, and a2. when vehicle is in rectilinear and curvilinear motion by implementing a road slope observer based on a linear Kalman filter, which is designed to: a21. operate based on signals indicative of vehicle speed and acceleration, and a22. compensate for accelerometric disturbances due to; a221. vehicle static pitch resulting from vehicle load distribution, and a222. vehicle dynamic pitch due to acceleration to which vehicle is subjected during motion, and a223. accelerometric disturbance components due to vehicle lateral dynamics; b. vehicle mass is estimated: b1. when vehicle is in motion, and b2. based on a recursive least square algorithm with forgetting factor, and b3. based on an accelerometric signal indicative of vehicle acceleration, on a vehicle speed signal, and other signals representing a vehicle propulsive/resistive torque, and b4. at different low gears, to provide a mass estimation and an associated variance for each gear, and b5. based on mass estimations and corresponding variances for each gear, and b6. compensating for accelerometer disturbances due to: b61, vehicle dynamic pitch; and b62. accelerometrie disturbance components due to vehicle lateral dynamics; and b7. minimizing uncertainties on propulsive/resistive torque due to gear efficiency and roiling resistance.
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Citations
13 Claims
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1. Automotive electronic control unit (ECU) programmed to real-time estimate vehicle mass based on a vehicle acceleration signal from an accelerometer, a vehicle speed signal, and other signals representing a vehicle propulsive/resistive torque;
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wherein vehicle mass is estimated; a1. when the vehicle is in motion, a2. compensating for accelerometric disturbances due to; a21. vehicle dynamic pitch; and a22. accelerometric components due to vehicle lateral dynamics; and a3. based on a recursive least square algorithm with forgetting factor inputted with a compensated vehicle acceleration signal, and a4. at different low gears, to estimate vehicle mass and associated variance for each gear, and a5. based on vehicle mass estimations and corresponding variances for each gear, and a6. minimizing uncertainties on propulsive/resistive torque due to gear efficiency and rolling resistance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
wherein the vehicle is considered stopped in the presence of substantially zero values of the vehicle speed signal; b2. when the vehicle is in rectilinear and curvilinear motion; b21. compensating for accelerometric disturbances due to; b211. vehicle static pitch resulting from vehicle load distribution, and b212. vehicle dynamic pitch due to acceleration to which vehicle is subjected during motion, and b213. accelerometric disturbance components due to vehicle lateral dynamics; b3. implementing a road slope observer based on a linear Kalman filter inputted with the vehicle speed signal and the compensated vehicle acceleration signal.
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3. The automotive electronic control unit (ECU) according to claim 2, further programmed to:
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c. link road slope estimation carried out when vehicle is considered stopped and in motion; c1. starting road slope estimation when vehicle is stopped based on the latest road slope estimations when vehicle was in motion, and c2. starting road slope estimation when vehicle is in motion based on the latest road slope estimations when vehicle was stopped.
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4. The automotive electronic control unit (ECU) according to claim 2, further programmed to:
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d. either estimate road slope and vehicle mass independently, or e. estimate road slope based on vehicle mass estimation.
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5. The automotive electronic control unit (ECU) according to claim 2, further programmed to estimate road slope:
b4. when vehicle is in curvilinear motion; b41. for vehicle lateral acceleration values comprised in a predetermined range, b42. using the road slope observer as per point b3, b43. having compensated accelerometric disturbances due to vehicle lateral acceleration.
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6. The automotive electronic control unit (ECU) according to claim 2, further programmed to compensate for accelerometric disturbances due to vehicle static and dynamic pitches:
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b214. estimating vehicle static pitch resulting from the vehicle load distribution based on estimated vehicle mass and attitudes diagram, and b215. estimate vehicle dynamic pitch based on the vehicle acceleration signal during motion.
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7. The automotive electronic control unit (ECU) according to claim 1, further programmed to estimate vehicle mass:
a7. limiting dynamic pitch effects and accelerometric disturbances effects due to vehicle lateral acceleration on vehicle mass estimation.
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8. The automotive electronic control unit (ECU) according to claim 1, wherein vehicle mass estimation is carried out as a weighted average of individual mass estimations at different gear engaged, and wherein to estimated vehicle mass is associated an overall variance computed as an average of individual variances associated with individual mass estimations.
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9. The automotive electronic control unit (ECU) according to claim 1, wherein vehicle mass is estimated when vehicle is in motion and only when propulsive/resistive torque is considered reliable, and wherein vehicle mass estimation is considered to be reliable when overall variance of estimated vehicle mass is lower than a threshold value.
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10. The automotive electronic control unit (ECU) according to claim 1, wherein vehicle mass is estimated when vehicle is in motion and is considered to be reliable even when vehicle successively stops.
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11. The automotive electronic control unit (ECU) according to claim 1, wherein vehicle mass is estimated every time that predetermined events occur that make unreliable the previous vehicle mass estimation.
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12. A vehicle comprising an automotive electronic control unit (ECU) according to claim 1.
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13. A software loadable into an automotive electronic control unit (ECU) and designed to cause, when executed, the automotive electronic control unit to become programmed as claimed in claim 1.
Specification