Ground load estimation device, control device, and ground load estimation method
AssigneeHitachi Astemo, Ltd.
InventorsYuichiro Minakuchi, Vaibhav Gupta
Life of this patent
Estimating the term…
Abstract
The present invention achieves a technique that makes it possible to estimate a ground contact load of a vehicle with sufficiently high accuracy. A ground contact load estimation device (100) acquires a wheel angular speed, a steady load, and an inertia load of a vehicle, uses the steady load and the inertia load to cause a first gain calculation section (122) to calculate a first gain, multiplies a variation in wheel angular speed by a second gain so as to cause a tire effective radius variation calculation section (121) to calculate a tire effective radius variation, and multiplies the tire effective radius variation by the first gain so as to estimate a road surface load.
Claims13
A ground contact load estimation device for estimating a ground contact load of a vehicle with reference to a road surface load of the vehicle,
- said ground contact load estimation device comprising:
- a processor comprising:
- an acquisition section including a wheel speed sensor that acquires a wheel angular speed of the vehicle, and configured to acquire a physical quantity which is related to the vehicle and includes the wheel angular speed, a jerk of the vehicle, a steady load of the vehicle, and an inertia load of the vehicle;
- and
- a road surface load estimation section including (i) a first gain calculation section configured to use at least the steady load and the inertia load, which are included in the physical quantity that has been acquired by the acquisition section, to calculate a first gain indicative of at least rigidity of a wheel of the vehicle, (ii) a second gain correction section configured to use a value of the wheel speed sensor to calculate a slip ratio-related value of the vehicle so as to correct, in accordance with at least the slip ratio-related value and the jerk, a second gain for reducing an influence of a variation in wheel angular speed on an estimation result, and (iii) a tire effective radius variation calculation section configured to calculate a tire effective radius variation by multiplying, by the second gain, a variation in wheel angular speed, which has been acquired by the acquisition section, the road surface load estimation section being configured to estimate the road surface load of the vehicle by multiplying the tire effective radius variation by the first gain;
- and
- wherein the ground contact load estimation device controls one or more other devices of the vehicle.
A ground contact load estimation method for estimating a ground contact load of a vehicle with reference to a road surface load of the vehicle, said
- ground contact load estimation method comprising the steps of:
- acquiring a physical quantity which is related to the vehicle and includes a wheel angular speed of the vehicle, a jerk of the vehicle, a steady load of the vehicle, and an inertia load of the vehicle;
- using at least the steady load and the inertia load to calculate a first gain indicative of at least rigidity of a wheel of the vehicle;
- using the wheel angular speed to calculate a slip ratio-related value of the vehicle so as to correct, in accordance with at least the slip ratio-related value and the jerk, a second gain for reducing an influence of a variation in wheel angular speed on an estimation result;
- calculating a tire effective radius variation by multiplying a variation in wheel angular speed by the second gain;
- and
- estimating the road surface load by multiplying the tire effective radius variation by the first gain;
- and
- controlling one or more other devices of the vehicle.
Dependencies are inferred from the claim text.