Patent Description:
When activated, however, ESA systems will often necessitate a drop in steering force provided by the system prior to providing an additional steering force needed to avoid the object. This drop not only causes a delay in providing the additional steering force but may also be disconcerting for a driver of the vehicle (e.g., they may feel as though the power steering has failed).

Aspects described below include a method of evasive steering assist (ESA) that is performed by a vehicle. The method comprises determining, based on sensor data received from one or more sensors that are local to the vehicle, at least one of a state or an environment of the vehicle over time, the sensor data comprising steering input by a driver of the vehicle. The method also comprises predicting, based on the state or the environment of the vehicle at a first time, that a collision between the vehicle and an object is imminent, entering, based on the prediction that the collision with the object is imminent, a pre-active phase, causing, during the pre-active phase, a power-steering system to adjust a steering force provided by the power-steering system to supplement a driver steering force by: causing, during a first pre-active sub-phase of the pre-active phase, the steering force to be zero; and causing, during a second pre-active sub-phase of the pre-active phase, the steering force to be similar to that of an inactive phase or higher than that of the inactive phase. The method further comprises determining, based on the state or the environment of the vehicle at a second time indicating that a steering angle of the vehicle at the second time is insufficient to avoid the collision, that the collision between the vehicle and the object is imminent, entering, based on the determination that the collision with the object is imminent, an active phase, and causing, during the active phase, the power-steering system to adjust the steering force supplementing the driver steering force effective to steer the vehicle to avoid the collision with the object.

Aspects described below also include a system for ESA of a vehicle. The system comprises one or more sensors configured to produce sensor data indicating at least one of a state of the vehicle over time or an environment of the vehicle over time. The system additionally comprises a power-steering system configured to provide a steering force to the vehicle. The system also comprises at least one processor and at least one computer-readable storage medium comprising instructions that, when executed by the processor, cause the system to predict, based on the state or the environment of the vehicle at a first time, that a collision between the vehicle and an object is imminent. The instructions further cause the system to enter, based on the prediction that the collision with the object is imminent, a pre-active phase and cause, during the pre-active phase, the power-steering system to adjust the steering force provided by the power-steering system to supplement a driver steering force by: causing, during a first pre-active sub-phase of the pre-active phase, the steering force to be zero; and causing, during a second pre-active sub-phase of the pre-active phase, the steering force to be similar to that of an inactive phase or higher than that of the inactive phase. The instructions also cause the system to determine, based on the state or the environment of the vehicle at a second time indicating that a steering angle of the vehicle at the second time is insufficient to avoid the collision, that the collision between the vehicle and the object is imminent, enter, based on the determination that the collision with the object is imminent, an active phase; and cause, during the active phase, the power-steering system to adjust the steering force supplementing the driver steering force effective to steer the vehicle to avoid the collision with the object.

Apparatuses and techniques enabling evasive steering assist (ESA) with a pre-active phase are described with reference to the following drawings. The same numbers are used throughout the drawings to reference like features and components:.

Evasive steering assist (ESA) systems enable vehicles to determine that collisions with objects are imminent and provide steering forces in order to avoid the collisions. Often times, however, these systems (or portions thereof) require a drop in steering force provided by the systems when enacted. The drop in steering force causes delays in applying additional steering forces needed to avoid the collisions while simultaneously causing drivers a perception of loss of steering support.

Techniques and systems are described that enable ESA with a pre-active phase. An ESA system predicts that a collision with an object is imminent and enters a pre-active phase. The pre-active phase causes the required drop in steering force to occur prior to determining that the collision is imminent. At a later time, the ESA system determines that the collision is imminent and enacts an active phase. The active phase causes a steering force effective to avoid the collision. By enacting the pre-active phase prior to the determination of the imminent collision, the ESA system may provide the additional steering force needed to avoid the collision without delay while simultaneously shielding a driver of vehicle from feeling the drop in steering force.

<FIG> is an example process flow <NUM> of ESA with a pre-active phase. The process flow <NUM> is generally implemented by an ESA system <NUM> of a vehicle <NUM>, which is discussed further in regard to <FIG>.

The process flow <NUM> starts with the ESA system <NUM> in an inactive phase <NUM>. In the inactive phase <NUM>, the ESA system <NUM> is inactive such that vehicle <NUM> is operating in a standard driving mode (e.g., standard power steering force). In the illustrated example, the vehicle <NUM> is an object <NUM>. Although the ESA system <NUM> is considered to be inactive during the inactive phase <NUM>, it may still monitor aspects of the vehicle and the environment of the vehicle.

As the vehicle <NUM> approaches the object <NUM>, the ESA system <NUM>, while in the inactive phase <NUM>, predicts that a collision with the object <NUM> is imminent (prediction <NUM>). The prediction <NUM> may be based on sensor data from one or more sensors of the vehicle <NUM>. For example, the prediction <NUM> may be in response to the ESA system <NUM> detecting that a forward collision warning (FCW) is active. The prediction <NUM> may further be based on detecting that a driver input to a steering wheel of the vehicle <NUM> has surpassed a threshold (e.g., a rapid angular velocity or acceleration is detected). It should be noted that the prediction <NUM> would not cause a conventional ESA system to activate and/or provide additional steering forces.

Based on the prediction <NUM>, the ESA system <NUM> enters a pre-active phase <NUM>. The pre-active phase <NUM> causes a power-steering system of the vehicle to drop a steering force provided by the power-steering system and then ramp up to a pre-active steering force. The pre-active steering force may correspond to that of the inactive phase <NUM> (e.g., a standard power steering force) or may be slightly above that of the inactive phase <NUM>. If the pre-active steering force is configured to be higher than that of the inactive phase <NUM>, the additional steering force is generally not enough to be felt by the driver. For example, the additional steering force (on top of the standard power steering force) may correspond to less than five Newton-meters (Nm) at the steering wheel. It should be noted that conventional ESA systems do not include the pre-active phase <NUM> and, therefore, these other systems cause an associated power-steering system to drop the steering force after determining that a collision with an object <NUM> is imminent (determination <NUM>).

As the vehicle <NUM> continues to approach the object <NUM>, the ESA system <NUM> determines that the collision with the object <NUM> is imminent (determination <NUM>) while in the pre-active phase <NUM>. The determination <NUM> may be based on a distance to the object <NUM> and a steering angle of the vehicle (e.g., angle of the front wheels relative to the vehicle <NUM>). For example, it may be determined that the vehicle <NUM> is turning, or has turned, the steering wheel an insufficient amount to avoid the object <NUM>. In other words, the turning is not sufficient to avoid the object <NUM>. As mentioned above, the determination <NUM> is when conventional ESA systems would activate, thus, causing the drop in steering force to occur after the determination <NUM>.

Based on the determination <NUM>, the ESA system <NUM> enters an active phase <NUM>. The active phase <NUM> causes the power-steering system to apply a steering force effective to steer the vehicle <NUM> around the object <NUM>. However, because the power-steering system of the vehicle is caused to drop the steering force prior to the active phase <NUM>, e.g., during the pre-phase <NUM>, the drop may not be felt by the driver. Furthermore, the additional steering forces needed to avoid the object <NUM> may be applied immediately after the determination <NUM>.

<FIG> is an example illustration <NUM> of a trajectory and steering forces of a vehicle using ESA with the pre-active phase <NUM>. The example illustration <NUM> follows the example process flow <NUM> and comprises two parts: a trajectory portion <NUM> and a steering force portion <NUM>. The trajectory portion <NUM> shows a trajectory <NUM> of the vehicle <NUM> in avoiding the object <NUM>. The steering force portion <NUM> shows steering forces that affect the trajectory <NUM>. The trajectory portion <NUM> and the steering force portion <NUM> share a time axis (e.g., time <NUM>) in order to show a correlation between the steering forces the trajectory <NUM>. The trajectory portion <NUM> has a coordinate system of up the page as the vehicle <NUM> steering left and down the page as the vehicle <NUM> steering right. Similarly, the steering force portion <NUM> has a coordinate system of up the page or positive as being a steering force to steer the vehicle <NUM> left and down the page or negative as being a steering force to steer the vehicle <NUM> to the right.

The inactive phase <NUM>, the pre-active phase <NUM>, and the active phase <NUM> are indicated in relation to the time <NUM>. In between the phases are times corresponding to the prediction <NUM> and the determination <NUM>. An inflection point <NUM> where the ESA system <NUM> (not shown) will reverse a steering force to steer the vehicle <NUM> back to an original direction (e.g., a swerve) is also indicated with its corresponding time. A final point <NUM>, where the vehicle <NUM> is generally traveling in the same direction as when it started the process, albeit offset from the object <NUM>, is also indicated with its corresponding time. The shape of the trajectory <NUM> may vary depending on implementation and circumstances. For example, the ESA system <NUM> may be configured to turn but not swerve (e.g., the trajectory <NUM> would be a straight-line tangent at the inflection point <NUM>).

The steering force portion <NUM> shows an ESA steering force <NUM>, a driver steering force <NUM>, and a total steering force <NUM>. The ESA steering force <NUM> is the difference between the total steering force <NUM> and the driver steering force <NUM>. It should be noted that the driver steering force <NUM> may be zero for any portion or all of the time frame of the process without departing from the scope of this disclosure.

A portion of the steering force portion <NUM> is enlarged at <NUM>. As shown, the driver steering force <NUM> is initiated at initial point <NUM>. For example, the driver may see the object <NUM> and begin to turn the steering wheel, thus providing the driver steering force <NUM>. The ESA steering force <NUM> in the inactive phase <NUM> corresponds to a standard power-steering force. Although the ESA steering force <NUM> is shown as a flat line entering the prediction <NUM>, the ESA steering force <NUM> could be any shape in the inactive phase <NUM> without departing from the scope of the disclosure.

The prediction <NUM> is determined, and the ESA system <NUM> enters the pre-active phase <NUM>. A first pre-active sub-phase <NUM> causes the ESA steering force <NUM> to be set to a low value at drop <NUM>. The drop <NUM> may correspond to an ESA steering force of zero. Because there is a driver steering force <NUM> at a time corresponding to the drop <NUM>, the total steering force <NUM> becomes the driver steering force <NUM> at the drop <NUM>.

The driver steering force <NUM> is shown as non-zero at the time of the prediction <NUM> in order to show the drop <NUM> in the ESA steering force <NUM>. If no driver steering force <NUM> is present at the time of the prediction <NUM>, then the ESA steering force <NUM> would be zero at the time of the prediction (based on the standard power steering force of the inactive mode <NUM>), and, thus, the total steering force <NUM> would be zero when the prediction <NUM> occurs. In this scenario, the drop <NUM> would disappear as the ESA system <NUM> would set the ESA steering force <NUM> to the low value of the drop <NUM>, thereby taking the ESA steering force <NUM> from zero to zero.

After the drop <NUM>, a second pre-active sub-phase <NUM> causes the ESA steering force <NUM> to rise to a pre-active steering force <NUM>. The pre-active steering force <NUM> corresponds to a steering force at or slightly above the ESA steering force <NUM> provided during the inactive phase <NUM>. If the pre-active steering force <NUM> is elevated relative to the inactive phase <NUM>, the additional ESA steering force <NUM> may correspond to <NUM>-<NUM> at a steering wheel of the vehicle. The torque applied by the ESA system <NUM> at the steering wheel is unlikely to be noticed by a driver. In some implementations, the second pre-active sub-phase <NUM> may not occur due to the determination <NUM> being made during the first pre-active sub-phase. In this case, the ESA system <NUM> would simply transition to the active phase <NUM> during the first pre-active sub-phase <NUM>.

When the determination <NUM> is made, the ESA system <NUM> enters the active phase <NUM>. The active phase <NUM> causes the ESA steering force <NUM> to climb to an active steering force <NUM> that will cause the vehicle to avoid the object <NUM>. Once the object <NUM> has been avoided, the ESA system <NUM> may return to the inactive phase <NUM> (e.g., be deactivated until another prediction <NUM> is made).

By enabling the pre-active phase <NUM>, the ESA system <NUM> is able to immediately begin climbing to the active steering force <NUM> when the determination <NUM> is made. It should be noted that the shapes of the trajectory <NUM> and the steering forces (<NUM>, <NUM>, and <NUM>) are shown for example only. The shapes, magnitudes, and time frames may vary widely based on situation and implementation without departing from the scope of this disclosure. Regardless of the shapes, the three phases and their transitions still occur.

<FIG> is an example illustration <NUM> of example data flows and actions during the inactive phase <NUM>, the pre-active phase <NUM>, and the transition therebetween. The example illustration <NUM> starts with the ESA system <NUM> in the inactive phase <NUM>. While in the inactive phase <NUM>, sensor data <NUM> is received by an ESA module <NUM>. The sensor data <NUM> may comprise data from local sensors that indicate a state of the vehicle <NUM> or an environment around the vehicle <NUM>. The sensor data <NUM> may be received by a prediction module <NUM> that monitors the sensor data <NUM> to determine if the prediction <NUM> should be made.

In the inactive phase <NUM>, the ESA module <NUM> may not provide any inputs to a power-steering system <NUM> of the vehicle <NUM>. That is, while the ESA system <NUM> is in the inactive phase <NUM>, the power-steering system <NUM> operates as it normally would, for example, by providing a standard steering force <NUM>.

The prediction module <NUM> makes the prediction <NUM> that the collision with the object <NUM> is imminent. Based on making the prediction <NUM>, the ESA system <NUM> transitions to the pre-active phase <NUM>.

While in the pre-active phase <NUM>, the ESA module <NUM> communicates with the power-steering system <NUM>. The communication causes the power-steering system <NUM> to provide the drop <NUM> in the ESA steering force <NUM> and the pre-active steering force <NUM>.

<FIG> is an example illustration <NUM> of example data flows and actions during the pre-active phase <NUM>, the active phase <NUM>, and the transition therebetween. The illustration <NUM> starts with the ESA system <NUM> in the pre-active phase <NUM>. While in the pre-active phase <NUM>, the sensor data <NUM> is received by the ESA module <NUM>. The sensor data <NUM> may be received by a determination module <NUM> that monitors the sensor data <NUM> to determine if the determination <NUM> should be made.

Based on the sensor data <NUM>, the determination module <NUM> makes the determination <NUM> that the collision with the object <NUM> is imminent. Although shown as outputting the pre-active steering force <NUM>, as discussed above, the determination may be made prior to getting to the pre-active steering force, for example, during the first pre-active sub-phase <NUM>. Based on making the determination <NUM>, the ESA system <NUM> transitions to the active phase <NUM>.

In some scenarios, the determination <NUM> may not be made. For example, while in the pre-active phase <NUM>, the driver may steer enough to avoid the object <NUM>, and thus, never trigger the determination. In this case, the ESA system <NUM> may return to the inactive phase <NUM>. Because the pre-active phase <NUM> is barely noticeable by the driver, entering and exiting the pre-active phase <NUM> without transitioning to the active phase <NUM> is minorly disrupting to a driver, if at all.

While in the active phase <NUM>, the ESA module <NUM> communicates with the power-steering system <NUM>. The communication causes the power-steering system <NUM> to provide the active steering force <NUM>, which is effective to avoid the collision with the object <NUM>.

<FIG> illustrates, at <NUM>, an example of the ESA system <NUM> in which ESA with the pre-active phase <NUM> can be implemented. Although the vehicle <NUM> is illustrated as a car, the vehicle <NUM> may comprise any vehicle (e.g., a truck, a bus, a boat, a plane, etc.) without departing from the scope of this disclosure. As shown underneath, the ESA system <NUM> of the vehicle <NUM> includes at least one processor <NUM>, at least one computer-readable storage medium <NUM>, one or more sensors <NUM>, the power-steering system <NUM>, the ESA module <NUM>, and optionally a third-party ESA component <NUM>.

The processor <NUM> (e.g., an application processor, microprocessor, digital-signal processor (DSP), or controller) executes instructions <NUM> (e.g., code) stored within the computer-readable storage medium <NUM> (e.g., a non-transitory storage devices such as a hard drive, SSD, flash memory, read-only memory (ROM), EPROM, or EEPROM) to cause the ESA system <NUM> to perform the techniques described herein. The instructions <NUM> may be part of an operating system and/or one or more applications of the ESA system <NUM>.

The instructions <NUM> cause the ESA system <NUM> to act upon (e.g., create, receive, modify, delete, transmit, or display) data <NUM> (e.g., application data, module data; sensor data, or I/O data). Although shown as being within the computer-readable storage medium <NUM>, portions of the data <NUM> may be within a random-access memory (RAM) or a cache of the ESA system <NUM> (not shown). Furthermore, the instructions <NUM> and/or the data <NUM> may be remote to the ESA system <NUM>.

The ESA module <NUM> (or portions thereof) may be comprised by the computer-readable storage medium <NUM> or be a stand-alone component (e.g., executed in dedicated hardware in communication with the processor <NUM> and computer-readable storage medium <NUM>). For example, the instructions <NUM> may cause the processor <NUM> to implement or otherwise cause the ESA module <NUM> to receive the sensor data <NUM> and transition between the phases, as described in regard to <FIG>.

The sensors <NUM>, which provide the sensor data <NUM>, may be any type of sensors, detectors, or code. For example, the sensors <NUM> may comprise a ranging sensor to detect a range and/or location of the object <NUM>. The sensors <NUM> may also comprise a potentiometer on a steering column of the vehicle to determine a steering input or rapid input by the driver. Furthermore, the sensors <NUM> may comprise code that determines if functions or components of the vehicle are active, e.g., the FCW being activated or not.

The power-steering system <NUM> may be any type of system known by those of ordinary skill in the art. For example, the power-steering system may be hydraulic or electric, with column, rack, or steering-box-mounted actuators. Regardless of implementation, the power-steering system <NUM> provides steering forces to the vehicle, which may be driver-initiated or initiated by the ESA module <NUM>.

The optional third-party ESA component <NUM> is representative of an original equipment manufacturer (OEM) or third-party ESA component (e.g., hardware, software, system, or function). For example, the ESA module <NUM> may interface with the third-party ESA component <NUM> to cause the power-steering system <NUM> to apply the ESA steering force <NUM>. For example, the ESA module <NUM> may make the prediction <NUM> and cause the third-party ESA component <NUM> to activate. By doing so, the ESA module <NUM> may cause the third-party ESA component <NUM> to initiate the drop <NUM> and the pre-active steering force <NUM>. Similarly, the third-party ESA component <NUM> may make the determination and initiate the active steering force <NUM>. Without the ESA module <NUM> communicating with the third-party ESA component <NUM>, the third-party ESA component <NUM> would wait until the determination <NUM> to activate, thus causing the drop <NUM> to occur after the determination <NUM>, which, as discussed above, is not optimal.

<FIG> illustrates an example method <NUM> for ESA with the pre-active phase <NUM>. Method <NUM> may be implemented utilizing the previously described examples, such as the process flow <NUM>, the illustrations <NUM>, <NUM>, and <NUM>, and the ESA system <NUM>. Operations <NUM> through <NUM> may be performed by one or more entities (e.g., the ESA system <NUM>, the ESA module <NUM>, or the third-party ESA component <NUM>). The order in which the operations are shown and/or described is not intended to be construed as a limitation, and any number or combination of the operations can be combined in any order to implement the method <NUM> or an alternate method.

The method <NUM> generally starts in an inactive state (e.g., the inactive state <NUM>). At <NUM>, a state or an environment of a vehicle at a first time is determined, and a prediction is made that a collision with an object is imminent. For example, the ESA module <NUM> may receive the sensor data <NUM> and make the prediction <NUM>.

At <NUM>, a pre-active phase is entered based on the prediction that the collision with the object is imminent. For example, the ESA module <NUM> may cause the ESA system <NUM> to enter the pre-active phase <NUM>. In some implementations, the third-party ESA component <NUM> may be activated (but not tasked to provide evasive steering).

At <NUM>, a steering force provided by a power-steering system is adjusted. For example, the ESA module <NUM> may cause the power-steering system <NUM> to output the drop <NUM> in the ESA steering force <NUM> and the pre-active steering force <NUM>. In some implementations, the drop <NUM> and the pre-active steering force <NUM> are implemented via the third-party ESA component <NUM>.

At <NUM>, the state or the environment of the vehicle at a second time is determined, and a determination is made that the collision with the object is imminent. For example, the ESA module <NUM> or the third-party ESA component <NUM> may receive the sensor data <NUM> and make the determination <NUM>.

At <NUM>, an active phase is entered based on the determination that the collision with the object is imminent. For example, the ESA module <NUM> may cause the ESA system <NUM> to enter the active phase <NUM>. In some implementations, the active phase <NUM> enables the third-party ESA component <NUM> to provide evasive steering.

At <NUM>, the steering force provided by the power-steering system is adjusted effective to steer the vehicle to avoid the collision with the object. For example, the ESA module <NUM> may cause the power-steering system <NUM> to output the active steering force <NUM>. Alternatively, the third-party ESA component <NUM> may cause the power-steering system <NUM> to output the active steering force <NUM>.

Claim 1:
A method of evasive steering assist (ESA) performed by a vehicle (<NUM>), the method comprising:
determining, based on sensor data (<NUM>) received from one or more sensors that are local to the vehicle (<NUM>), at least one of a state or an environment of the vehicle (<NUM>) over time, the sensor data (<NUM>) comprising steering input by a driver of the vehicle (<NUM>);
predicting, based on the state or the environment of the vehicle (<NUM>) at a first time, that a collision between the vehicle (<NUM>) and an object (<NUM>) is imminent;
entering, based on the prediction that the collision with the object (<NUM>) is imminent, a pre-active phase (<NUM>);
causing, during the pre-active phase (<NUM>), a power-steering system (<NUM>) to adjust a steering force (<NUM>) provided by the power-steering system (<NUM>) to supplement a driver steering force (<NUM>) by:
causing, during a first pre-active sub-phase (<NUM>) of the pre-active phase (<NUM>), the steering force (<NUM>) to be zero; and
causing, during a second pre-active sub-phase (<NUM>) of the pre-active phase (<NUM>), the steering force (<NUM>) to be similar to that of an inactive phase (<NUM>) or higher than that of the inactive phase (<NUM>);
determining, based on the state or the environment of the vehicle (<NUM>) at a second time indicating that a steering angle of the vehicle (<NUM>) at the second time is insufficient to avoid the collision, that the collision between the vehicle (<NUM>) and the object (<NUM>) is imminent;
entering, based on the determination that the collision with the object (<NUM>) is imminent, an active phase (<NUM>); and
causing, during the active phase (<NUM>), the power-steering system (<NUM>) to adjust the steering force (<NUM>) supplementing the driver steering force (<NUM>) effective to steer the vehicle (<NUM>) to avoid the collision with the object (<NUM>).