# US 10,870,356 B2 · Vehicle-speed control device

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- Number: US 10,870,356 B2
- Document ID: US10870356B2
- Status: Granted
- Kind: B2
- Application number: 15/761,159
- Filed: 2016-09-12
- Published: 2018-09-20
- Granted: 2020-12-22
- Earliest claimed: 2015-10-26
- Assignees: Mitsubishi Electric Corporation
- Applicants: Mitsubishi Electric Corporation
- Inventors: Kazuto Yokoyama; Masahiro Iezawa
- Web page: https://patentgrep.com/patent/US10870356B2

## CPC

- B60L 9/18: fed from DC supply lines
- B60L 15/20: for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
- B60L 15/2045: {for optimising the use of energy}
- H02P 5/50: by comparing electrical values representing the speeds
- H02P 5/51: Direct ratio control
- B60L 2220/42: with use of more than one motor
- B60L 2240/421: Speed
- B60L 2240/423: Torque
- B60W 10/08: including control of electric propulsion units, e.g. motors or generators
- B60W 30/20: Reducing vibrations in the driveline
- Y02T 10/64: Electric machine technologies in electromobility
- Y02T 10/72: Electric energy management in electromobility
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A vehicle speed control unit includes feedback control parts, the number of feedback control parts corresponding to the number of multiple motors, generating feedback command torques for the respective motors, on the basis of respective deviations between speed signals from speed sensors detecting revolution speeds of the multiple motors and feedback target vehicle-speed signal reshaped from the inputted target vehicle-speed signal by target vehicle-speed filters; a feedforward control part calculating a feedforward command torque for the vehicle as a whole, on the basis of the inputted target vehicle-speed signal; and a torque distribution part dividing the feedforward command torque into individual feedforward command torques for distribution to the respective motors, wherein the individual feedforward command torques are respectively added to the feedback command torques and, to control the respective motors.

## Claims

### Claim 1

A vehicle speed controller comprising:
a processor configured to:
control multiple motors driving wheels of a vehicle provided with the multiple motors so that a speed of the vehicle follows a vehicle speed indicated by a target vehicle speed signal being input;
generate feedback command torques for feedback controlling each of the multiple motors, based on a respective deviation between a speed signal from a speed sensor detecting a revolution speed of each of the multiple motors and a feedback target vehicle speed signal obtained by passing the inputted target vehicle speed signal through a target vehicle speed filter, to feedback-control the multiple motors;
calculate a feedforward command torque for feedforward controlling the vehicle using a transfer function whose input is the inputted target vehicle speed signal and whose output is the feedforward command torque for the vehicle; and
divide the feedforward command torque into individual feedforward command torques for distribution to the multiple motors,
wherein the transfer function used in calculating the feedforward command torque is a product of a transfer function of the target vehicle speed filter used in generating the feedback command torques multiplied by an inverse model of a transfer function of the vehicle, the transfer function of the vehicle having as an input a summation of forces in a direction of translational motion of the vehicle and having as an output the vehicle speed, and
wherein the processor respectively adds the individual feedforward command torques to the feedback command torques for the multiple motors, to control the multiple motors.

### Claim 2 (depends on 1)

The vehicle speed controller of claim 1, wherein the processor respectively generates feedback command torques for the multiple motors, based on respective deviations between the speed signals and individual feedback target vehicle speed signals for the multiple motors driving the wheels that are corrected from the feedback target vehicle speed signal reshaped from the inputted target vehicle speed signal by the target vehicle speed filter, based on the speed of and a yaw rate of the vehicle, and geometric positional relations of the contact points with the ground of, steering angles of, and sideslip angles of the wheels.

### Claim 3 (depends on 2)

The vehicle speed controller of claim 2, wherein in a case the vehicle includes total four wheels of right and left pairs of front and rear wheels and with the multiple motors for respectively driving the right and left pairs of wheels via differential gears, the processor calculates respective target vehicle speeds for the four wheels and then average the target vehicle speeds for the right and left pairs of wheels as corrected feedback target vehicle speeds for the right and left pairs of wheels.

### Claim 4 (depends on 1)

The vehicle speed controller of claim 1, wherein the feedback control of the multiple motors respectively includes integral controls, and the processor decreases gains of the integral controls with increase of the revolution speeds of the multiple motors and/or increase of a steering angle of the vehicle.

### Claim 5 (depends on 1)

The vehicle speed controller of claim 1, wherein the processor decreases the feedforward command torque, based on a relative speed between the vehicle and an obstacle detected by an obstacle detection sensor detecting a distance to and the obstacle ahead of or behind the vehicle.

### Claim 6 (depends on 5)

The vehicle speed controller of claim 5, wherein the processor decreases the feedforward command torque, based on an inter-vehicle time based on a relative distance or a relative speed between the vehicle and the obstacle detected by the obstacle detection sensor.

### Claim 7 (depends on 1)

The vehicle speed controller of claim 1, wherein a control characteristic of at least one of the feedback controls of the multiple motors has a different control characteristic in at least either one of gain and phase from at least another one of the feedback controls.

### Claim 8 (depends on 7)

The vehicle speed controller of claim 7, wherein among the feedback controls, a feedback control of a motor driving one front wheel or two front wheels of the wheels and a feedback control of a motor driving one rear wheel or two rear wheels of the wheels have different control characteristics from each other.

### Claim 9 (depends on 7)

The vehicle speed controller of claim 7, wherein the different control characteristics are frequency characteristics.

### Claim 10 (depends on 1)

The vehicle speed controller of claim 1, wherein the speed signals from the speed sensors are the speed signals that are respectively filtered by speed signal filters for the multiple motors.

### Claim 11 (depends on 1)

The vehicle speed controller of claim 1, wherein the processor respectively adds the individual feedforward command torques to the feedback command torques, to control the multiple motors according to command torques that are respectively filtered from the added individual feedforward command torques, by torque filters for the multiple motors.

### Claim 12 (depends on 1)

The vehicle speed controller of claim 1, wherein the processor determines, based on an acceleration/deceleration of the vehicle speed indicated by the feedback target vehicle speed signal, a ratio of an individual feedforward command torque to be distributed to a motor driving a front wheel of the wheels or a summation of the individual feedforward command torques to be distributed to motor driving front wheels of the wheels to an individual feedforward command torque to be distributed to a motor driving a rear wheel of the wheels or a summation of the individual feedforward command torques to be distributed to the multiple motors driving rear wheels of the wheels.

### Claim 13

A vehicle speed control method comprising:
controlling multiple motors driving wheels of a vehicle provided with the multiple motors so that a speed of the vehicle follows a vehicle speed indicated by a target vehicle speed signal being input;
generating feedback command torques for feedback controlling each of the multiple motors, based on a respective deviation between a speed signal from a speed sensor detecting a revolution speed of each of the multiple motors and a feedback target vehicle speed signal obtained by passing the inputted target vehicle speed signal through a target vehicle speed filter, to feedback-control the multiple motors;
calculating a feedforward command torque for feedforward controlling the vehicle using a transfer function whose input is the inputted target vehicle speed signal and whose output is the feedforward command torque for the vehicle;
dividing the feedforward command torque into individual feedforward command torques for distribution to the multiple motors; and
respectively adding the individual feedforward command torques to the feedback command torques for the multiple motors to control the multiple motors,
wherein the transfer function used in calculating the feedforward command torque is a product of a transfer function of the target vehicle speed filter used in generating the feedback command torques multiplied by an inverse model of a transfer function of the vehicle, the transfer function of the vehicle having as an input a summation of forces in a direction of translational motion of the vehicle and whose having as an output the vehicle speed.