# US 11,993,262 B2 · Crawl operations for four-wheel steering vehicles

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- Number: US 11,993,262 B2
- Document ID: US11993262B2
- Status: Granted
- Kind: B2
- Application number: 17/039,224
- Filed: 2020-09-30
- Published: 2022-03-31
- Granted: 2024-05-28
- Earliest claimed: 2020-09-30
- Assignees: Ford Global Technologies, LLC
- Applicants: Ford Global Technologies, LLC
- Inventors: Patrick Gordon Collins
- Web page: https://patentgrep.com/patent/US11993262B2

## CPC

- B60W 30/18063: {Creeping}
- B60K 1/02: comprising more than one electric motor
- B60K 17/348: having differential means for driving one set of wheels, e.g. the front, at one speed and the other set, e.g. the rear, at a different speed (B60K17/346 takes precedence)
- B60K 17/354: having separate mechanical assemblies for transmitting drive to the front or to the rear wheels or set of wheels
- B60K 17/356: having fluid or electric motor, for driving one or more wheels
- B60K 17/358: {all driven wheels being steerable}
- B60W 10/04: including control of propulsion units
- B60W 10/20: including control of steering systems
- B62D 5/00: Power-assisted or power-driven steering (for non-deflectable wheels B62D11/00; fluid-pressure servomotors in general F15B)
- B62D 7/1509: {with different steering modes, e.g. crab-steering, or steering specially adapted for reversing of the vehicle}
- B62D 7/1581: {characterised by comprising an electrical interconnecting system between the steering control means of the different axles}
- B62D 7/159: {characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition}
- B62D 9/00: Steering deflectable wheels not otherwise provided for (steering positon indicators B62D15/02)
- B60K 1/00: Arrangement or mounting of electrical propulsion units (B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00)
- B60K 2001/001: {one motor mounted on a propulsion axle for rotating right and left wheels of this axle}
- B62D 17/00: Means on vehicles for adjusting camber, castor, or toe-in
- 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
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M)

## Abstract

Crawl operations for four-wheel steering vehicles are described herein. An example vehicle described herein includes four wheels, a front steering actuator to turn the front wheels, a rear steering actuator to turn the rear wheels, a front drive motor to drive the front wheels, and a rear drive motor to drive the rear wheels. The vehicle also includes an electronic control unit (ECU) to activate the front steering actuator to turn the front wheels in a first direction, activate the rear steering actuator to turn the rear wheels in a second direction opposite the first direction such that the front wheels and the rear wheels are turned in opposite directions, activate the front drive motor to drive the front wheels in a reverse direction, and activate the rear drive motor to drive the rear wheels in a forward direction while the front wheels are driven in the reverse direction.

## Claims

### Claim 1

A vehicle comprising:
a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel;
a front steering actuator to turn the left and right front wheels;
a rear steering actuator to turn the left and right rear wheels;
a front drive motor to drive the left and right front wheels;
a rear drive motor to drive the left and right rear wheels; and
an electronic control unit (ECU) programmed to:
activate the front steering actuator to turn the left and right front wheels in a first direction;
activate the rear steering actuator to turn the left and right rear wheels in a second direction opposite the first direction such that the left and right front wheels and the left and right rear wheels are turned in opposite directions; and
while the left and right front wheels are turned in the first direction and the left and right rear wheels are turned in the second direction, activate the front drive motor to drive the left and right front wheels in a reverse direction and activate the rear drive motor to drive the left and right rear wheels in a forward direction such that the left and right front wheels are driven in the reverse direction while the left and right rear wheels are driven in the forward direction.

### Claim 2 (depends on 1)

The vehicle of claim 1, further including a yaw sensor, the ECU programmed to modulate power to the front and rear drive motors based on measurements from the yaw sensor to limit rotation of the vehicle.

### Claim 3 (depends on 1)

The vehicle of claim 1, further including a rear differential lock and a front differential lock, the ECU programmed to activate the front and rear differential locks prior to activating the front and rear drive motors.

### Claim 4 (depends on 1)

The vehicle of claim 1, wherein the ECU is programmed to activate the front and rear steering actuators and activate the front and rear drive motors in response to a request for a left crawl operation or right crawl operation from a driver.

### Claim 5 (depends on 4)

The vehicle of claim 4, wherein:
when the request is for the left crawl operation, the ECU is programmed to activate the front steering actuator to turn the left and right front wheels to the right and activate the rear steering actuator to turn the left and right rear wheels to the left; and
when the request is for the right crawl operation, the ECU is programmed to activate the front steering actuator to turn the left and right front wheels to the left and activate the rear steering actuator to turn the left and right rear wheels to the right.

### Claim 6 (depends on 4)

The vehicle of claim 4, wherein the ECU is programmed to deactivate the left crawl operation or the right crawl operation in response to a cancel command from the driver.

### Claim 7 (depends on 4)

The vehicle of claim 4, wherein the ECU is programmed to deactivate the left crawl operation or the right crawl operation in response to determining the vehicle has gained traction.

### Claim 8 (depends on 7)

The vehicle of claim 7, further including one or more torque sensors associated with one or more of the wheels, the ECU programmed to determine the vehicle has gained traction based on measurements from the one or more torque sensors.

### Claim 9

A non-transitory machine readable medium comprising instructions that, when executed, cause an electronic control unit (ECU) of a vehicle to:
activate a front steering actuator of the vehicle to turn front wheels of the vehicle in a first direction;
activate a rear steering actuator of the vehicle to turn rear wheels of the vehicle in a second direction opposite the first direction such that the front wheels and the rear wheels are turned in opposite directions;
activate a front drive motor to drive the front wheels in a reverse direction; and
activate a rear drive motor to drive the rear wheels in a forward direction while the front drive motor is activated and driving the front wheels in the reverse direction and while the left and right front wheels are turned in the first direction and the left and right rear wheels are turned in the second direction.

### Claim 10 (depends on 9)

The non-transitory machine readable medium of claim 9, wherein the instructions, when executed, cause the ECU to modulate power to the front and rear drive motors based on measurements from a yaw sensor to limit rotation of the vehicle.

### Claim 11 (depends on 9)

The non-transitory machine readable medium of claim 9, wherein the instructions, when executed, cause the ECU to, prior to activating the front and rear drive motors, activate front and rear differential locks.

### Claim 12 (depends on 9)

The non-transitory machine readable medium of claim 9, wherein the instructions, when executed, cause the ECU to, prior to activating the front and rear steering actuators and the front and rear drive motors, determine whether the vehicle is stopped.

### Claim 13

A vehicle comprising:
a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel;
a left front steering actuator to turn the left front wheel;
a right front steering actuator to turn the right front wheel;
a left rear steering actuator to turn the left rear wheel;
a right rear steering actuator to turn the right rear wheel;
a front drive motor to drive the left and right front wheels;
a rear drive motor to drive the left and right rear wheels; and
an electronic control unit (ECU) programmed to:
activate the left front steering actuator and the left rear steering actuator to turn the left front wheel and the left rear wheel, respectively, in a first direction;
activate the right front steering actuator and the right rear steering actuator to turn the right front wheel and the right rear wheel, respectively, in a second direction while the left front wheel and the left rear wheel are turned in the first direction; and
while the left front wheel and the left rear wheel are turned in the first direction and the right front wheel and the right rear wheel are turned in the second direction, activate the front drive motor and the rear drive motor to drive the left and right front wheels and the left and right rear wheels, respectively, in a same direction.

### Claim 14 (depends on 13)

The vehicle of claim 13, further including a yaw sensor, the ECU programmed to modulate power to the front and rear drive motors based on measurements from the yaw sensor to limit rotation of the vehicle.

### Claim 15 (depends on 13)

The vehicle of claim 13, further including a rear differential lock and a front differential lock, the ECU programmed to activate the front and rear differential locks prior to activating the front and rear drive motors.

### Claim 16 (depends on 13)

The vehicle of claim 13, wherein the ECU is programmed to activate the left front steering actuator, the right front steering actuator, the left rear steering actuator, the right rear steering actuator, the front drive motor, and the rear drive motor in response to a request for a forward crawl operation or a reverse crawl operation from a driver.

### Claim 17 (depends on 16)

The vehicle of claim 16, wherein, when the request is for the forward crawl operation, the ECU is programmed to:
activate the left front steering actuator and the left rear steering actuator to turn the left front wheel and the left rear wheel, respectively, to the right;
activate the right front steering actuator and the right rear steering actuator to turn the right front wheel and the right rear wheel, respectively, to the left; and
activate the front and rear drive motors to drive the left and right front wheels and the left and right rear wheels, respectively, in a forward direction.

### Claim 18 (depends on 17)

The vehicle of claim 17, wherein, when the request is for the reverse crawl operation, the ECU is programmed to:
activate the left front steering actuator and the left rear steering actuator to turn the left front wheel and the left rear wheel, respectively, to the left;
activate the right front steering actuator and the right rear steering actuator to turn the right front wheel and the right rear wheel, respectively, to the right; and
activate the front and rear drive motors to drive the left and right front wheels and the left and right rear wheels, respectively, in a reverse direction.

### Claim 19 (depends on 16)

The vehicle of claim 16, wherein the ECU is programmed to deactivate the forward crawl operation or the reverse crawl operation in response to a command from the driver.

### Claim 20 (depends on 16)

The vehicle of claim 16, wherein the ECU is programmed to deactivate the left crawl operation or the right crawl operation in response to determining the vehicle has gained traction.