Methods and systems that use electronic power steering units to intervene in steering to prevent vehicle rollover or loss of control.

Abstract

A vehicle steering intervention system and method prevent a vehicle run-off condition or a vehicle rollover condition. The system includes a driver input torque sensor to sense a torque applied to a steering wheel by a driver, a steering angle sensor to sense a steering angle, and a speed determining device to determine a vehicle speed. An electronic power steering unit includes an electronic processor and a memory. The electronic power steering unit determines a vehicle steering intervention threshold based on the sensed torque, steering angle, and vehicle speed. The electronic power steering unit predicts whether the vehicle steering intervention threshold will be exceeded within a predetermined time based on a torque gradient and / or a steering angle gradient. When the vehicle steering intervention threshold is predicted to be exceeded, the electronic power steering unit reduces power steering assist and / or provides a counter-steering force.

Description

Background Technology

[0001] This arrangement relates to a system and method for providing steering intervention during vehicle operation by minimizing vehicle turning or movement that could lead to vehicle rollover or loss of control. Summary of the Invention

[0002] The vehicle's electronic power steering unit is configured to determine a rollover condition or loss of control and prevent the vehicle from rolling over or losing control, such as spinning, by reducing power steering assistance and / or by providing a counter-steering force when the steering wheel is manipulated too forcefully. In one example, the vehicle is operating at a speed greater than 50 miles per hour. A rapid and large turn or force applied to the steering wheel could cause the vehicle to roll over or lose control. The electronic power steering unit is configured to determine such a condition and act immediately to prevent the vehicle from rolling over or losing control. Other vehicles may use a driver assistance system domain controller or other components to perform rollover calculations. Such an arrangement requires more time to calculate, react, and provide anti-rollover control to the vehicle.

[0003] One embodiment is a vehicle steering intervention system for preventing loss of control or rollover of a vehicle. The vehicle steering intervention system includes: a driver input torque sensor for sensing torque applied to the steering device by the driver; a steering angle sensor for sensing the steering angle; a speed determination device for determining the vehicle speed; and an electronic power steering unit including an electronic processor and a memory. The electronic processor is configured to: determine a vehicle steering intervention threshold based on the steering angle, vehicle speed, and the torque sensed by the driver input torque sensor, and execute a predictive model. The predictive model includes determining a torque gradient of the torque sensed by the driver input torque sensor, predicting based on the torque gradient whether the vehicle steering intervention threshold will be exceeded within a predetermined time, and when the predicted vehicle steering intervention threshold will be exceeded within the predetermined time, the electronic processor reduces power steering assistance and / or provides a counter-steering force to the steering device to avoid loss of control or rollover.

[0004] Another embodiment is a method for providing steering intervention to a vehicle. The method includes: sensing torque applied to a steering device by a driver using a driver input torque sensor, sensing a steering angle, determining a vehicle speed, and determining a vehicle steering intervention threshold using an electronic power steering unit based on the steering angle, vehicle speed, and torque sensed by the driver input torque sensor. The method includes determining a torque gradient of the torque sensed by the driver input torque sensor; predicting, based on the torque gradient, whether the vehicle steering intervention threshold will be exceeded within a predetermined time using a predictive model stored in the electronic power steering unit; and when the prediction indicates that the vehicle steering intervention threshold will be exceeded within the predetermined time, configuring the electronic power steering unit to reduce power steering assistance and / or provide a counter-steering force to the steering device to avoid loss of control or vehicle rollover.

[0005] Other aspects, features, and embodiments will become apparent from consideration of the detailed description and accompanying drawings. Attached Figure Description

[0006] Figure 1 The diagram illustrates a block diagram of one embodiment of a vehicle steering intervention system that eliminates loss of vehicle control or rollover.

[0007] Figure 2 The illustration shows a flowchart of an embodiment of an electronic power steering unit that provides vehicle steering intervention;

[0008] Figure 3 The diagram illustrates a flowchart of additional feature sensing used to determine the vehicle steering intervention threshold. Detailed Implementation

[0009] Before explaining any embodiment in detail, it should be understood that this disclosure is not intended to limit its application to the construction details and component arrangements set forth in the following description or illustrated in the following drawings. Embodiments can have other configurations and can be practiced or implemented in various ways.

[0010] Various embodiments can be implemented using multiple hardware and software-based devices and multiple different structural components. Furthermore, embodiments may include hardware, software, and electronic components or modules, which, for the purposes of discussion, may be illustrated and described as if most components were implemented solely in hardware. However, those skilled in the art, and based on reading this detailed description, should recognize that in at least one embodiment, the electronic aspects of the invention may be implemented in software executable by one or more electronic controllers (e.g., stored on a non-transitory computer-readable medium). For example, the terms "unit," "control unit," and "controller" described in the specification may include one or more electronic controllers, one or more memories including a non-transitory computer-readable medium, one or more input / output interfaces, one or more application-specific integrated circuits (ASICs) and other circuitry, and various connections or connectors (e.g., wires, traces, and buses) connecting the various components.

[0011] Figure 1 A block diagram view of a vehicle steering intervention system 40 for controlling vehicle steering is shown. In one embodiment, the vehicle steering intervention system 40 includes an electronic power steering unit 44. The electronic power steering unit 44 includes an electronic processor 50 and a memory 54. The memory 54 includes one or more memory modules, such as random access memory (“RAM”) and electrically erasable programmable read-only memory (“EEPROM”). An input / output interface 56 transmits and receives information via a communication bus 60. The electronic processor 50 processes information by executing one or more applications or modules. The applications or modules may be stored in the memory 54 as instructions or commands. The electronic processor 50 also stores information generated by the applications in the memory 54. An electronic steering control element 58, such as a power steering control motor, is connected to and controlled by the electronic power steering unit 44.

[0012] Figure 1 The communication bus 60 shown is a FlexRay automotive communication bus, a Controller Area Network (CAN) bus, or other type of communication link between multiple control units, sensors, and other devices. In some embodiments, the communication bus 60 connects the electronic power steering unit 44 to a driver input torque sensor 64, which senses or provides the force applied to the steering wheel by the driver. A steering angle sensor 70 is connected to the communication bus 60 to provide steering wheel positioning to the electronic power steering unit 44. In one embodiment, the steering angle sensor 70 is deployed on the steering column of the steering device. In another embodiment, the steering angle sensor 70 is configured to sense the rotation of a planetary gear fixed to the vehicle's steering shaft. In yet another embodiment, the steering angle sensor 70 determines the steering angle based on the motor rotation of the power steering control motor and its ratio relative to the rack and planetary gears.

[0013] In one embodiment, vehicle speed determining device 74 determines vehicle speed. In another embodiment, vehicle speed determining device 74 is a vehicle speed sensor. In yet another embodiment, calculation of other information provides vehicle speed. In one embodiment, vehicle latitude / longitude acceleration sensor 78 senses vehicle acceleration. Vehicle speed and acceleration are provided to the input / output interface 56 of electronic power steering unit 44 via communication bus 60.

[0014] Figure 1 A rack force determination device 82 for sensing rack forces on wheels is shown. In another embodiment, the rack force is calculated based on other information provided in the vehicle. A camera-based road detection system 86 senses video and various other sensed images to determine the presence of low-friction surfaces, such as snow, ice, gravel, and puddles on the road. The camera-based road detection system 86 includes a processor and memory to process the images and determine road conditions. In some embodiments, an external temperature sensor assists in determining the presence of ice or snow. The rack force determination device 82 and the camera-based road detection system 86 are connected to the electronic power steering unit 44 via a communication bus 60.

[0015] Furthermore, Figure 1 A driver assistance system domain controller 90 is shown. The driver assistance system domain controller 90 (DASy) implements traffic jam assist and highway assist features for the vehicle. In some embodiments, the driver assistance system domain controller 90 provides electronic stability control for the vehicle. Response time to changes in vehicle steering is enhanced by providing processing of vehicle steering intervention at the electronic power steering unit 44.

[0016] operate

[0017] Figure 2 It shows Figure 1 Flowchart 100 showing the operation of the electronic power steering unit 44. Although Figure 1 A single electronic power steering unit 44 is shown, but multiple control units and / or electronic processors can perform [the action]. Figure 2 The various functions shown. Multiple electronic processors in the electronic power steering unit 44 can be used to enable... Figure 2 The multiple steps shown occur essentially simultaneously or in parallel.

[0018] Figure 2A flowchart 100 illustrates the initial operation of the vehicle steering intervention system 40. At step 104, in one embodiment, the electronic processor 50 receives, via the communication bus 60, the torque applied by the driver to the vehicle steering wheel, sensed by the driver input torque sensor 64. Subsequently, at step 108, the electronic processor 50 determines or calculates the torque gradient (change in torque).

[0019] exist Figure 2 At step 112, as shown, the electronic processor 50 is configured to receive the steering angle sensed by the steering angle sensor 70 via the communication bus 60. In one embodiment, the electronic processor 50 proceeds to step 116 and determines or calculates the gradient of the steering angle.

[0020] The electronic processor then proceeds to step 120, where it receives the vehicle speed from the vehicle speed determination device 74 via the communication bus 60. The electronic processor 50 then proceeds to step 124.

[0021] At step 124, the electronic processor 50 is configured to execute an algorithm to determine a vehicle steering intervention threshold. In one embodiment, the vehicle steering intervention threshold is based on at least the steering angle, vehicle speed, and torque sensed by the driver input torque sensor 64. In one embodiment, the determination of the vehicle steering intervention threshold is performed using a lookup table that includes values ​​for torque, steering angle, and vehicle speed. In another embodiment, the determination of the vehicle steering intervention threshold is performed using an equation that includes variables corresponding to at least torque, steering angle, and vehicle speed, specific to the vehicle's brand and model. In yet another embodiment, a three-dimensional graph is used to determine the steering intervention threshold.

[0022] The electronic processor 50 proceeds to decision step 140 to predict, using a predictive model stored in memory 54 of the electronic power steering unit 44, based on torque gradients and / or steering angle gradients, whether a vehicle steering intervention threshold will be exceeded within a predetermined time. The gradient(s) or derivative(s) over the predetermined time provide a prediction of the future positioning of the vehicle's steering arrangement. When steering intervention is unnecessary at decision step 140, the procedure operated by the electronic processor 50 returns to step 104, and torque is determined again based on steering, and steps 108, 112, 116, 120, and 124 are repeated.

[0023] When the prediction indicates that the vehicle steering intervention threshold will be exceeded within a predetermined time, the electronic processor 50 proceeds to step 144. At step 144, the power steering unit of the electronic processor 50 reduces power steering assistance by decreasing the force on the electronic steering control 58 and / or providing a counter-steering force to the electronic steering control 58 to avoid loss of control or vehicle rollover. The electronic processor 50 then returns to step 104 to repeat the prediction process.

[0024] The electronic processor 50 prevents sudden changes in steering direction to avoid loss of vehicle control or rollover. The electronic processor 50 executes a predictive model by determining that the torque gradient and / or steering angle gradient have values ​​(one or more) that will exceed the vehicle steering intervention threshold within a predetermined time.

[0025] (one or more) additional optional embodiments

[0026] Figure 3 A flowchart 200 shows an additional embodiment of vehicle steering intervention. Figure 3 Steps 204, 208, 212, 216, and 220 in the text are... Figure 1 Steps 104, 108, 112, 116, and 120 shown are the same. Therefore, there is no need to describe them further.

[0027] like Figure 3 As shown at step 221, electronic processor 50 receives the friction force value of the road surface from camera-based road detection system 86 via communication bus 60. Electronic processor 50 proceeds to step 222 to receive vehicle acceleration from vehicle latitude / longitude acceleration sensor 78 via communication bus 60. Electronic processor 50 proceeds to step 223.

[0028] exist Figure 3 At step 223, as shown, the rack force determined by the rack force determining device 82 is provided to the electronic processor 50 via the communication bus 60. The electronic processor 50 is then configured to proceed to step 224.

[0029] At step 224, the electronic processor 50 executes an algorithm to determine the vehicle steering intervention threshold. Figure 3 In this embodiment, the vehicle steering intervention threshold is based on steering angle, vehicle speed, rack force, vehicle acceleration, road surface friction, and torque sensed by the driver input torque sensor 64. The electronic processor 50 then proceeds to an additional step (not shown) corresponding to decision step 140, and as... Figure 2 The other steps 144 shown above provide steering intervention if necessary, as discussed above.

[0030] In another embodiment, the vehicle steering intervention threshold is based on the steering angle, vehicle speed, rack force determined by rack force determination device 82, vehicle model stored in memory 54, and torque sensed by driver input torque sensor 64. In yet another embodiment, the vehicle steering intervention threshold is based on the steering angle, vehicle speed, vehicle acceleration, and torque sensed by driver input torque sensor 64. In still another embodiment, the vehicle steering intervention threshold is based on the steering angle, vehicle speed, road surface friction, and torque sensed by driver input torque sensor 64. In some embodiments, the vehicle steering intervention threshold depends on the vehicle brand / model, and in some cases, further depends on the driving mode.

[0031] Figure 2 and 3 The steps shown in the embodiments are provided for illustrative purposes. These steps can be performed in entirely different orders. In one embodiment, the determination of the steering angle gradient is not performed, and therefore steps 116 and 216 are not included. In some embodiments, the road surface friction, rack force, and acceleration are not determined. Therefore, in some embodiments, steps 221, 222, and 223 are optional.

[0032] Although not specifically discussed in this article, returning the steering wheel to a position that orients the vehicle for straight-line travel typically does not approach the stability threshold because the likelihood of rollover is reduced when the vehicle is moving in a straight line. This arrangement is primarily intended to prevent sudden and large changes in vehicle direction that could lead to rollover or loss of control.

[0033] It should be understood that although the components are described as logically separate, such description is for illustrative purposes only. In some embodiments, the illustrated components may be combined or divided into separate software, firmware, and / or hardware. Regardless of how they are combined or divided, these components may execute on the same computing device or be distributed across different computing devices connected via one or more networks or other suitable communication means.

[0034] Various features, advantages and embodiments are set forth in the following claims.

Claims

1. A vehicle steering intervention system for preventing loss of control or rollover of a vehicle, the vehicle steering intervention system comprising: A driver input torque sensor is used to sense the torque applied to the steering device by the driver; Steering angle sensor, used to sense steering angle; Vehicle speed determination equipment, used to determine vehicle speed; and The electronic power steering unit includes an electronic processor and a memory, wherein the electronic processor is configured to: The vehicle steering intervention threshold is determined based on the steering angle, vehicle speed, and torque sensed by the driver input torque sensor. The prediction model is executed using the following methods: Determine the torque gradient of the torque sensed by the torque sensor input by the driver. The steering angle gradient is determined based on the steering angle sensed by the steering angle sensor. Based on torque gradient and steering angle gradient, predict whether the vehicle steering intervention threshold will be exceeded within a predetermined time, and When it is predicted that the vehicle steering intervention threshold will be exceeded within a predetermined time, the power steering assist will be reduced and / or a counter-steering force will be provided to the steering device to avoid loss of control or vehicle rollover.

2. The vehicle steering intervention system of claim 1, wherein the steering angle sensor is deployed on the steering column of the steering device, or the steering angle sensor is based on the motor rotation of the power steering control motor and its ratio relative to the rack and planetary gears.

3. The vehicle steering intervention system of claim 1, wherein the steering angle sensor is configured to sense the rotation of a planetary gear fixed to the vehicle steering axis to move the rack.

4. The vehicle steering intervention system of claim 1, wherein the vehicle steering intervention system includes a rack force determination device for determining rack force, wherein the electronic processor is configured to determine a vehicle steering intervention threshold based on steering angle, vehicle speed, rack force, vehicle model, and torque sensed by a driver input torque sensor.

5. The vehicle steering intervention system of claim 1, comprising a vehicle latitude / longitude acceleration sensor for sensing vehicle acceleration, wherein the electronic processor is configured to determine a vehicle steering intervention threshold based on steering angle, vehicle speed, vehicle acceleration, and torque sensed by a driver input torque sensor.

6. The vehicle steering intervention system of claim 1, comprising a camera-based road detection system for determining road surface friction, wherein the electronic processor is configured to determine a vehicle steering intervention threshold based on steering angle, vehicle speed, road surface friction, and torque sensed by a driver input torque sensor.

7. The vehicle steering intervention system of claim 1, comprising a communication bus connecting an electronic power steering unit including an electronic processor to a driver input torque sensor, a steering angle sensor, and a vehicle speed determination device.

8. A method for providing steering intervention to a vehicle, the method comprising: The torque applied to the steering system by the driver is sensed using a driver input torque sensor; Sensing steering angle; Determine the vehicle speed; The vehicle steering intervention threshold is determined using the electronic power steering unit based on the steering angle, vehicle speed, and torque sensed by the driver input torque sensor. Determine the torque gradient of the torque sensed by the torque sensor input by the driver; Using a prediction model stored in the electronic power steering unit, it is predicted, based on the torque gradient, whether the vehicle steering intervention threshold will be exceeded within a predetermined time. and When it is predicted that the vehicle steering intervention threshold will be exceeded within a predetermined time, the electronic power steering unit is configured to reduce power steering assistance and / or provide a counter-steering force to the steering device to avoid loss of control or vehicle rollover. The method includes determining the steering angle gradient, and the prediction of whether a vehicle steering intervention threshold will be exceeded within a predetermined time is based on the torque gradient and the steering angle gradient.

9. The method of claim 8, wherein the steering angle is sensed by a steering angle sensor deployed on the steering column of the steering device.

10. The method of claim 8, wherein the steering angle is sensed by a steering angle sensor configured to sense rotation of a planetary gear fixed to the steering shaft to move the rack.

11. The method of claim 8, wherein the method comprises sensing rack force using a rack force determining device, and The determination of the vehicle steering intervention threshold is based on steering angle, vehicle speed, rack force, vehicle model, and torque sensed by the torque sensor input by the driver.

12. The method of claim 8, wherein the method comprises sensing vehicle acceleration using a vehicle latitude / longitude acceleration sensor, and The determination of the vehicle steering intervention threshold is based on the steering angle, vehicle speed, vehicle acceleration, and torque sensed by the torque sensor input by the driver.

13. The method of claim 8, wherein the method comprises using a camera-based road detection system to determine the frictional force of the road surface, and The determination of the vehicle steering intervention threshold is based on torque, steering angle, vehicle speed, and road friction.

14. The method of claim 8, the method comprising connecting an electronic power steering unit including an electronic processor and a memory to a communication bus of a driver input torque sensor, a steering angle sensor, and a vehicle speed determination device.

15. The method of claim 14, the method comprising a driver assistance system domain controller connected to a communication bus.

16. The method according to claim 8, wherein the method comprises: The rack force is determined using a rack force determination device. Vehicle acceleration is detected using a vehicle latitude / longitude acceleration sensor, and A camera-based road detection system is used to sense the friction force on the road surface to determine the friction force. The determination of the vehicle steering intervention threshold is based on steering angle, vehicle speed, rack force, vehicle acceleration, road friction, and torque sensed by the torque sensor input by the driver.

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