Vehicle steering control system

Patent metadata

Field	Value
Publication number	US-9783229-B2
Application number	US-201514837000-A
Country	US
Kind code	B2
Filing date	Aug 27, 2015
Priority date	Aug 7, 2012
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A control system calculates inputs to a control target that has m inputs and n outputs (m=n, each of m and n is a natural number that is more than one), while designating a plurality of combinations of the inputs and the outputs. A feedback controller calculates, with respect to each designated combination, a control input to a non-interference controller based on a difference between a target value and a current value of the control quantity to make the current value follow the target value. The non-interference controller executes, with respect to each designated combination, a non-interference control to reduce influence due to mutual interference between n control quantities. This reduces the number of combinations of the inputs and the outputs, the combinations whose mutual interference needs considering; thereby, the non-interference control may be easily achieved.

First claim

What is claimed is:

1. A vehicle steering control system for a vehicle, comprising:
a steering system as a control target, configured to receive a plurality of m inputs and provide a plurality of n outputs based on the plurality of m inputs received, wherein each of m and n is a natural number that is more than one, m being equal to n, the plurality of m inputs including operation quantities, the plurality of n outputs including control quantities;
a plurality of feedback controllers, each of which is configured to calculate an operation quantity of the operation quantities based on a difference between (i) a target value, which is generated by a target value generator, the target value corresponding to a control quantity of the control quantities, and (ii) a current value of an output of the plurality of n outputs provided by the control target; and
a non-interference controller provided between (i) the plurality of feedback controllers and (ii) the control target, the non-interference controller being configured to execute a non-interference control to reduce influence due to mutual interference between the outputs provided by the control target,
wherein:
the plurality of n outputs provided by the control target include three control quantities that are (i) a steering angle, (ii) a yaw angle velocity, and (iii) a lateral acceleration, the three control quantities being vehicle properties of vehicle motions generated based on a driver's steering torque;
a plurality of combinations of the plurality of m inputs and the plurality of n outputs in the control target are designated by the vehicle steering control system; and
the non-interference control by the non-interference controller and the feedback control by the feedback controllers are configured to be executed with respect to each of the designated combinations of the plurality of m inputs and the plurality of n outputs,
wherein:
the control target includes a variable gear transfer steering motor which controls an actual steering angle of a front wheel, while one of the designated combinations is of (i) a motor voltage of the variable gear transfer steering motor that serves as one of the plurality of m inputs and (ii) the steering angle of the vehicle that serves as one of the plurality of n outputs;
the control target includes an electric power steering motor which assists a steering force by a driver, while one of the designated combinations is of (i) a motor voltage of the electric power steering motor that serves as one of the plurality of m inputs and (ii) the yaw angle velocity of the vehicle that serves as one of the plurality of n outputs; and
the control target includes an active rear steering motor which controls an actual steering angle of a rear wheel, while one of the designated combinations is of (i) a motor voltage of the active rear steering motor that serves as one of the plurality of m inputs and (ii) the lateral acceleration of the vehicle that serves as one of the plurality of n outputs.

2. The vehicle steering control system according to claim 1 , wherein:
the operation quantities are instructed voltages to actuators that drive the vehicle motions, whereas the control quantities are the vehicle properties of the vehicle motions; and
each combination among the designated combinations is of
(i) one input among the plurality of m inputs serving as the instructed voltages to actuators and
(ii) one output among the plurality of n outputs serving as the vehicle properties of the vehicle motions.

3. The vehicle steering control system according to claim 1 , wherein:
the number of the designated combinations is more than one and equal to n being the number of the plurality of n outputs, and thus equal to m being the number of the plurality of m inputs.

4. A vehicle steering control system for a vehicle, comprising:
a steering system as a control target that is configured to receive a plurality of m inputs and provide a plurality of n outputs based on the plurality of m inputs received, wherein each of m and n is a natural number that is more than one, m being equal to n, the plurality of m inputs including operation quantities, the plurality of n outputs including control quantities, the m inputs includes all inputs of the control target, and the n outputs includes all outputs of the control target;
a plurality of feedback controllers, each of which is configured to calculate an operation quantity of the operation quantities based on a difference between (i) a target value, which is generated by a target value generator, the target value corresponding to a control quantity of the control quantities, and (ii) a concurrent value of an output of the plurality of n outputs provided by the control target; and
a non-interference controller provided between (i) the plurality of feedback controllers and (ii) the control target, the non-interference controller being configured to execute a non-interference control to reduce influence due to mutual interference between the outputs provided by the control target,
wherein:
a plurality of combinations of the plurality of m inputs and the plurality of n outputs in the control target are designated by the vehicle steering control system, the operation quantities of the plurality of m inputs being instructed voltages to actuators that drive vehicle motions, the control quantities of the plurality of n outputs being vehicle properties of vehicle motions;
each combination among the designated plurality of combinations is of
(i) one input among the plurality of m inputs serving as the instructed voltages to actuators driving the vehicle motions and
(ii) one output among the plurality of n outputs serving as the vehicle properties of the vehicle motions;

the number of the designated plurality of combinations is more than one and equal to n being the number of the plurality of n outputs, and thus equal to m being the number of the plurality of m inputs; and
the non-interference control by the non-interference controller and the feedback control by the feedback controllers are configured to be executed with respect to each of the designated plurality of combinations of the plurality of m inputs and the plurality of n outputs.

5. The vehicle steering control system according to claim 4 , wherein:
the plurality of n outputs provided by the control target include three control quantities that are (i) a steering angle, (ii) a yaw angle velocity, and (iii) a lateral acceleration, the three control quantities being the vehicle properties of the vehicle motions generated based on a driver's steering torque.

6. The vehicle steering control system according to claim 5 , wherein:
the control target includes a variable gear transfer steering motor which controls an actual steering angle of a front wheel; and
the designated combination is of (i) a motor voltage of the variable gear transfer steering motor that serves as an input of the plurality of m inputs and (ii) the steering angle of the vehicle that serves as an output of the plurality of n outputs.

7. The vehicle steering control system according to claim 5 , wherein:
the control target includes an electric power steering motor which assists a steering force by a driver; and
the designated combination is of (i) a motor voltage of the electric power steering motor that serves as an input of the plurality of m inputs and (ii) the yaw angle velocity of the vehicle that serves as an output of the plurality of n outputs.

8. The vehicle steering control system according to claim 5 , wherein:
the control target includes an active rear steering motor which controls an actual steering angle of a rear wheel; and
the designated combination is of (i) a motor voltage of the active rear steer

Assignees

• Denso Corp
• Nat Univ Corp Nagoya Inst Of Tech

Inventors

• Mukai Yasuhiko
• Morita Yoshifumi
• Ukai Hiroyuki
• Iwasaki Makoto
• Wada Takeshi

Classifications

• B62D6/08

  responsive only to {driver} input torque · CPC title

• B62D6/003 Primary

  in order to control vehicle yaw movement, i.e. around a vertical axis (B62D6/007 takes precedence) · CPC title

• G05B15/02

  electric · CPC title

• B62D6/00

  Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits (means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00) · CPC title

• G05B11/58

  with inputs from more than one sensing element; with outputs to more than one correcting element · CPC title