Intelligent vehicle system and control logic for active brake drag mitigation for electromechanical brake systems

Abstract

This invention discloses an intelligent vehicle system and control logic for active braking resistance mitigation in an electromechanical braking system. Presented are an intelligent vehicle system specifying active braking resistance control, a method for manufacturing / using it, and a vehicle equipped with it. The method of operating a motorized vehicle with a brake-by-wire (BBW) system includes a vehicle controller determining whether the vehicle is traveling in the forward direction. If so, the controller responsively retrieves Advanced Driver Assistance System (ADAS) data and drive torque requirement data to determine whether an ADAS warning event has been detected or whether an acceleration torque requirement has been received to accelerate the vehicle. The controller commands the electric motor of the BBW braking system to drive the brake actuator, thereby changing the operating clearance (RC) between the brake pad and the brake rotor to a decreasing RC in response to the detection of an ADAS warning event, or to an increasing RC in response to the receipt of an acceleration requirement to accelerate the vehicle.

Description

Technical Field

[0001] This disclosure generally relates to braking systems for motor vehicles. More specifically, aspects of this disclosure relate to closed-loop feedback control systems and methods for mitigating braking resistance in brake-by-wire (BBW) vehicle braking systems. Background Technology

[0002] Currently manufactured motor vehicles, such as contemporary automobiles, are initially equipped with vehicle braking systems that operate to selectively slow down and eventually stop the vehicle. Automobiles have traditionally employed hydraulic or pneumatic braking systems, activated by the vehicle driver, or, for Advanced Driver Assistance Systems (ADAS) and Automated Vehicles (AV) applications, activated by an onboard vehicle controller. The most common type of braking system used in contemporary passenger vehicles is the friction braking system, in which a hydraulically actuated piston drives a brake pad or shoe ("friction braking element") into frictional engagement with a rotating drum or rotor ("rotating braking element"). For disc braking systems, a piston reciprocates within a brake caliper mounted to a steering knuckle, and a brake rotor is bolted to a spindle for rotation with the wheel unit. In doing so, the friction braking system converts the vehicle's kinetic energy into rotational and thermal energy from the frictional engagement of the friction braking element, thereby slowing / stopping the rotation of the corresponding wheel unit.

[0003] Some automobiles now employ decentralized “brake-by-wire” systems, replacing traditional hydraulic and pneumatic braking hardware with either electromechanical or electrohydraulic braking components. Electromechanical braking (EMB) systems (a subset of BBW) use a central brake system control module (BSCM), which activates individually motor-driven actuators located at each wheel corner module to provide the desired braking force at that wheel unit. For example, a ball screw type EMB system utilizes a BSCM-controlled motor to reciprocately drive the worm gear of a ball screw actuator into or away from the brake piston. In doing so, the brake piston engages and disengages with a friction brake pad using one of the EMB's brake rotors. During normal operation, when the brake pedal is released, the friction braking system may experience what is known as “brake resistance” (where the brake pad or shoe fails to fully disengage from the rotor or drum), causing unwanted friction and heat between the braking components. Summary of the Invention

[0004] This paper presents an intelligent transportation system with accompanying control logic for defining active braking resistance control, methods for manufacturing such a system, methods for operating such a system, and motor vehicles equipped with such a system. By way of example, but not limitation, the closed-loop feedback control system actively adjusts the operating clearance between the brake pads and their corresponding brake rotors of the EMB to minimize braking resistance, or, where possible, eliminate braking resistance entirely. A larger operating clearance can be implemented under selected vehicle operating conditions to reduce braking resistance, such as when a slower braking system response time is acceptable. To improve vehicle fuel efficiency and brake pad life, braking resistance can be minimized, for example, by increasing the operating clearance in driving scenarios where there is no braking requirement from the driver or advanced driver assistance systems (ADAS). Conversely, a smaller operating clearance can be implemented under other selected vehicle operating conditions to reduce the required piston stroke, such as when a faster braking system response time is deemed necessary. For example, upon detection of a forward impact, the operating clearance can be automatically reduced as anticipated by an emergency braking event. The operating clearance setting can be independently calibrated to the tested "primary" vehicle (e.g., brand, year, model, trim, etc.) and / or the tested braking system architecture (e.g., BBW, EMB, brake calipers, brake pads, etc.). To help maximize braking system efficiency and performance, the control system can dynamically adjust the optimal operating clearance in response to various driving scenarios, based on the available piston contraction control of the EMB system.

[0005] This disclosure relates to BBW vehicle braking systems, braking system control logic, and closed-loop feedback control techniques for active braking resistance control. In an example, a method for operating a motor vehicle equipped with a BBW braking system is presented. This representative method includes, in any order and combination of any of the options and features disclosed above and below: receiving, for example via a resident or remote microprocessor, central controller, control module, programmable logic device, integrated circuit (IC) device, or network of processors / controllers / modules / devices (collectively referred to as the "vehicle controller"), vehicle dynamics data indicating that the motor vehicle has been started by a key and is traveling in a forward direction; and, in response to confirmation of forward travel of the vehicle, receiving ADAS data (e.g., from an ADAS control module) and (e.g., from a throttle-by-wire (TBW) accelerator pedal) drive torque requirement (DTR) via the vehicle controller. ) data; from received ADAS and DTR data, for example via vehicle controller, determine whether an ADAS warning event (e.g., forward impact, lane departure, crossing the road, etc.) is detected and / or whether (e.g., from the driver or main vehicle) an acceleration torque request is received to accelerate the motor vehicle; and, for example via vehicle controller, command one or more electric brake motors of the BBW braking system to drive the corresponding brake actuators, and thereby change the operating clearance (RC) between the corresponding friction brake element and the rotating brake element either (1) to a reduced RC distance in response to the detection of an ADAS warning event; or (2) to an increased RC distance in response to the receipt of an acceleration request (which indicates that no braking request has been received).

[0006] Various aspects of this disclosure also relate to a computer-readable medium (CRM) containing controller-executable instructions for specifying dynamic adjustments to the friction brake operating clearance for active braking resistance control. In an example, a non-instantaneous CRM stores instructions executable by a vehicle controller of a motorized vehicle with a BBW braking system, including a brake motor that drives a brake actuator to press a friction brake element against a rotating brake element to slow / stop the vehicle. When executed, these CRM-stored instructions cause the system controller to perform operations including: receiving vehicle dynamics data indicating that the motor vehicle is traveling in the forward direction; receiving advanced driver assistance system (ADAS) data and drive torque request (DTR) data in response to the motor vehicle traveling in the forward direction; determining whether the ADAS data indicates that an ADAS warning event has been detected, and whether the DTR data indicates that an acceleration torque request has been received to accelerate the motor vehicle; and commanding the brake motor to drive the brake actuator, thereby changing the operating clearance between the friction brake element and the rotating brake element to a reduced RC distance in response to the detection of the ADAS warning event, or to an increased RC distance in response to the receipt of an acceleration torque request to accelerate the motor vehicle.

[0007] Additional aspects of this disclosure are dedicated to motor vehicles equipped with a BBW-EMB braking system for mitigating braking drag and closed-loop feedback control. As used herein, the terms "vehicle" and "motor vehicle" are used interchangeably and synonymously to refer to any relevant vehicle platform, such as passenger cars, commercial vehicles, industrial vehicles, rail vehicles, off-road and all-terrain vehicles, agricultural equipment, motorcycles, aircraft, spacecraft, etc. In the example, the motor vehicle includes a vehicle body with a passenger compartment, multiple road wheels attached to the vehicle body (e.g., via wheel corner modules coupled to an integral or frame-mounted chassis), and other standard original equipment. A prime mover is located inside the vehicle body and drives the road wheels to propel the vehicle; the prime mover may be essentially an electric traction motor and / or an internal combustion engine (ICE) assembly. The vehicle is also equipped with a BBW braking system comprising multiple EMB units, each operable to slow down a corresponding one of the vehicle's road wheels. Each EMB unit contains an electric servo motor that drives a ball screw actuator (BSA) assembly, thereby pushing the brake piston into the brake pad, causing the brake pad to press against the brake rotor, which is mounted to rotate simultaneously with its corresponding road wheel.

[0008] Continuing the discussion of the previous example, the vehicle is also equipped with a parked or remote vehicle controller, which is programmed to receive vehicle dynamic data and determine whether the motor vehicle is traveling in the forward direction. If so, the vehicle controller responsively receives ADAS data from the vehicle's onboard sensor array and DTR data from the driver input device, and uses this data to determine whether an ADAS warning event has been detected and whether an acceleration torque request has been received to accelerate the motor vehicle. The vehicle controller also commands the electric servo motors of the BBW braking system to drive their respective BSA components, thereby changing the operating clearance between their respective brake pads and brake rotors (e.g., in response to the detection of an ADAS warning event) to a decreasing or increasing RC distance, or (e.g., in response to receiving an acceleration torque request to accelerate the motor vehicle) to an increasing RC distance.

[0009] For any of the disclosed methods, CRM, and vehicles, the vehicle controller can also evaluate ADAS and DTR data to determine whether an ADAS warning event has been detected and whether an acceleration torque request has been received. In response to the absence of an ADAS warning event and the receipt of an acceleration torque request, the vehicle controller can receive vehicle lateral acceleration (VLA) data from the multi-axis accelerometers of the motor vehicle. In this example, the vehicle controller can evaluate the VLA sensor data to determine whether the current lateral acceleration of the motor vehicle exceeds a predefined VLA threshold (e.g., a force (g) of ~0.2g); if it does, the vehicle controller can responsively command each BBW brake motor to drive its brake actuator, thereby changing the operating clearance to a second (second) increased RC distance, which is greater than a first (first) increased RC distance.

[0010] For any of the disclosed methods, CRM, and vehicle, the vehicle controller can evaluate VLA and DTR data to determine whether the current lateral acceleration of the main vehicle is less than a predefined VLA threshold and whether the current speed of the main vehicle is less than a predefined speed threshold; if so, the vehicle controller can responsively command each brake motor to actuate its brake actuator, thereby changing the operating clearance to a third (3rd) increased RC distance, which is greater than both the first (1st) and second (2nd) RC distances. Alternatively, the vehicle controller can also receive steering wheel angle (SWA) sensor data from the steering wheel angle sensor of the vehicle's steer-by-wire (SBW) and evaluate the SWA data to determine whether the current SWA of the vehicle's steering wheel is less than a predefined SWA threshold (e.g., ~235°). In this example, commanding the brake motors to change the operating clearance to a third (3rd) increased RC distance further responds to the current SWA of the steering wheel being less than the predefined SWA threshold.

[0011] For any of the disclosed methods, CRM, and vehicle, the vehicle controller may receive vehicle ignition data indicating vehicle start-up before changing the operating clearance (e.g., from the Body Control Module (BCM)). In response to detecting vehicle start-up, the vehicle controller may command the brake motor to actuate its corresponding brake actuator, thereby setting the operating clearance to the default RC distance. Alternatively, after changing the RC to an increased RC distance, the vehicle controller may determine whether the primary vehicle is still traveling in the forward direction; if so, the vehicle controller may responsively determine whether another (new) acceleration torque request has been received. In response to not receiving a new acceleration request, the controller may command the brake motor to set the operating clearance to the default RC distance. The acceleration request may be received from the vehicle driver via driver input devices (e.g., accelerator pedal, cruise control button panel, etc.) and / or from an ADAS system control module (e.g., an adaptive cruise control (ACC) control module).

[0012] For any of the disclosed methods, CRM, and vehicles, the vehicle controller can evaluate received ADAS and DTR data to confirm that no braking request has been received from the vehicle driver or the vehicle's ADAS system. In this example, the vehicle controller can proactively adjust the operating clearance of the vehicle's braking system in response to confirming that no braking request has been received from the driver or the ADAS system. After detecting an ADAS warning event, the vehicle controller can evaluate new ADAS data to determine whether the ADAS warning event is no longer detected; once it is confirmed that the ADAS warning event is no longer detected, the vehicle controller can responsively command the brake motor of the BBW system to drive its corresponding brake actuator, thereby setting the operating clearance to the default RC distance.

[0013] For any of the disclosed methods, CRM, and vehicle, vehicle lateral acceleration can be monitored via a resident inertial measurement unit (IMU) containing a six-axis accelerometer and an integrated gyroscope. Instead of using accelerometer feedback for dynamic adjustment of RC, vehicle steering analysis can be obtained as a function of steering wheel angle and real-time vehicle speed. Furthermore, ADAS system data for detecting ADAS warning events can be obtained from a sensor array on the vehicle, which may include forward-facing vehicle cameras, forward-facing long-range radar sensors, forward-facing mid-range lidar sensors, ultrasonic sensors, side-mirror mounted side cameras, etc. In addition to the PCM and wheel speed sensors, vehicle dynamic data can be received from the engine control module (ECM), motor control module (MCM), body control module (BCM), PRNDL shift knob or shift disc, and / or IMU.

[0014] The present invention also discloses the following technical solutions: Option 1. A method of operating a motor vehicle having a brake-by-wire (BBW) braking system, the BBW braking system including a brake motor configured to drive a brake actuator to press a friction brake element against a rotating brake element, the method comprising: The vehicle controller receives vehicle dynamic data indicating that the motor vehicle is traveling in the forward direction; In response to the motor vehicle traveling in the forward direction, the vehicle controller receives advanced driver assistance system (ADAS) data and drive torque requirement (DTR) data for the motor vehicle. The vehicle controller determines whether the ADAS data indicates an ADAS warning event has been detected, and whether the DTR data indicates a received acceleration torque request to accelerate the motor vehicle; and The brake motor is commanded to drive the brake actuator, thereby changing the operating clearance (RC) between the friction brake element and the rotating brake element to a reduced RC distance in response to the detection of the ADAS warning event, or to a first increased RC distance in response to receiving the acceleration torque request to accelerate the motor vehicle.

[0015] Option 2. The method according to Option 1 further includes: The vehicle controller determines that the ADAS data indication has not detected the ADAS warning event, and determines that the DTR data indication has received the acceleration torque request to accelerate the motor vehicle; and In response to the absence of the ADAS warning event and the receipt of the acceleration torque request, the vehicle controller receives vehicle lateral acceleration (VLA) sensor data from the multi-axis accelerometer of the motor vehicle.

[0016] Option 3. The method according to Option 2 further includes: The vehicle controller determines whether the VLA sensor data indicates that the current VLA of the motor vehicle exceeds a predefined VLA threshold; and In response to the current VLA exceeding the predefined VLA threshold, the brake motor is commanded to drive the brake actuator, thereby changing the operating gap to a second increased RC distance, the second increased RC distance being greater than the first increased RC distance.

[0017] Option 4. The method according to Option 3 further includes: The vehicle controller determines, via the VLA sensor data, that the current VLA of the motor vehicle is less than a predetermined VLA threshold, and determines, via the DTR data, that the current vehicle speed is less than a predetermined speed threshold; and In response to the current VLA being less than the predetermined VLA threshold and the current vehicle speed being less than the predetermined speed threshold, the brake motor is commanded to drive the brake actuator, thereby changing the operating clearance to a third increased RC distance, the third increased RC distance being greater than the first increased RC distance and the second increased RC distance.

[0018] Option 5. The method according to Option 4 further includes: The vehicle controller receives steering wheel angle (SWA) sensor data from the steering wheel angle sensor of the motor vehicle; and The vehicle controller determines, via the vehicle controller, that the SWA sensor data indicates that the current SWA of the steering wheel is less than a predetermined SWA threshold, wherein, in further response to the current SWA of the steering wheel being less than the predetermined SWA threshold, the brake motor is commanded to change the operating clearance to the third increased RC distance.

[0019] Option 6. The method according to Option 1 further includes: Before changing the operating gap, the vehicle controller receives vehicle ignition data instructing the motor vehicle to start; and In response to the start of the motor vehicle, the brake motor is commanded to drive the brake actuator, thereby setting the operating clearance to the default RC distance.

[0020] Option 7. The method according to Option 1 further includes: After changing the RC to the first increased RC distance, the vehicle controller determines whether the motor vehicle is still traveling in the forward direction; In response to the determination that the motor vehicle is still traveling in the forward direction, the vehicle controller determines whether a new acceleration torque request should be received to accelerate the motor vehicle; and In response to the failure to receive the new acceleration torque request, the brake motor is commanded to drive the brake actuator, thereby setting the operating clearance to the default RC distance.

[0021] Option 8. The method according to Option 1, wherein the acceleration torque requirement is received from the driver via a driver input device and / or from the ADAS control module of the ADAS system.

[0022] Option 9. The method according to Option 1, further comprising determining, via the vehicle controller, from the ADAS data and the DTR data, that a braking request has not been received from the driver or ADAS control module of the motor vehicle, wherein in response to the absence of the braking request, it is determined whether the acceleration torque request has been received.

[0023] Option 10. The method according to Option 1 further includes: After the detection of the ADAS warning event, the vehicle controller determines whether the ADAS data indicates that the ADAS warning event will no longer be detected; and In response to no longer detecting the ADAS warning event, the brake motor is commanded to drive the brake actuator, thereby setting the operating clearance to the default RC distance.

[0024] Option 11. According to the method of Option 1, the vehicle dynamic data is received from the engine control module (ECM), powertrain control module (PCM), motor control module (MCM), body control module (BCM), and / or wheel speed sensors.

[0025] Option 12. The method according to Option 1, wherein the DTR data is received from an accelerator pedal sensor, and wherein the ADAS data is received from a vehicle sensor array, the vehicle sensor array including a forward-facing vehicle camera, a forward-facing long-range radar sensor, and / or a forward-facing mid-range lidar sensor.

[0026] Option 13. The method according to Option 1, wherein the brake motor is an electric servo motor, the brake actuator is a ball screw actuator (BSA) assembly engaging a brake piston, the friction braking element is a brake pad, and the rotating braking element is a brake rotor, wherein the electric servo motor drives the BSA assembly to move the brake piston, thereby changing the RC between the brake pad and the brake rotor.

[0027] Option 14. A non-transitory computer-readable medium storing instructions executable by a vehicle controller of a motor vehicle having a brake-by-wire (BBW) braking system, the BBW braking system including a brake motor configured to drive a brake actuator to press a friction brake element against a rotating brake element, the instructions, when executed, causing the vehicle controller to perform an operation including: Receive vehicle dynamic data indicating that the motor vehicle is traveling in the forward direction; In response to the motor vehicle traveling in the forward direction, it receives advanced driver assistance system (ADAS) data and drive torque requirement (DTR) data; Determine whether the ADAS data indicates that an ADAS warning event has been detected, and whether the DTR data indicates that an acceleration torque request has been received to accelerate the motor vehicle; and The brake motor is commanded to drive the brake actuator, thereby changing the operating clearance (RC) between the friction brake element and the rotating brake element to a reduced RC distance in response to the detection of the ADAS warning event, or to a first increased RC distance in response to receiving the acceleration torque request to accelerate the motor vehicle.

[0028] Option 15. A motorized vehicle, comprising: The vehicle itself; Multiple road wheels attached to the main body of the vehicle; A prime mover, which is attached to the vehicle body and configured to drive at least one of the road wheels, thereby propelling the motorized vehicle; A brake-by-wire (BBW) braking system, attached to the vehicle body and comprising a plurality of electromechanical brake (EMB) units, each EMB unit configured to slow down a corresponding one of the road wheels, each EMB unit including an electric servo motor configured to drive a ball screw actuator (BSA) assembly, thereby pushing a brake piston against a brake pad, such that the brake pad presses against a brake rotor mounted to rotate simultaneously with a corresponding one of the road wheels; and Vehicle controller, the vehicle controller being programmed to: Receive vehicle dynamic data indicating that the motor vehicle is traveling in the forward direction; In response to the motor vehicle traveling in the forward direction, the driver receives advanced driver assistance system (ADAS) sensor data from the vehicle sensor array and drive torque requirement (DTR) data from the driver input device. Determine whether the ADAS sensor data indicates the detection of an ADAS warning event, and whether the DTR data indicates the receipt of an acceleration torque request to accelerate the motor vehicle; and The electric servo motor is commanded to drive the BSA assembly, thereby changing the operating clearance (RC) between the brake pad and the brake rotor to a reduced RC distance in response to the detection of the ADAS warning event, or to a first increased RC distance in response to receiving the acceleration torque request to accelerate the motor vehicle.

[0029] Option 16. The motor vehicle according to Option 15, wherein the vehicle controller is further programmed to: Determine that the ADAS sensor data indicates no ADAS warning event was detected, and determine that the DTR data indicates the acceleration torque request was received to accelerate the motor vehicle; and In response to the absence of the ADAS warning event and the receipt of the acceleration torque request, vehicle lateral acceleration (VLA) sensor data is received from the multi-axis accelerometer of the motor vehicle.

[0030] Option 17. The motor vehicle according to Option 16, wherein the vehicle controller is further programmed to: Determine whether the VLA sensor data indicates that the current VLA of the motor vehicle exceeds a predefined VLA threshold; and In response to the current VLA exceeding the predefined VLA threshold, the electric servo motor is commanded to drive the BSA component, thereby changing the operating gap to a second increased RC distance, which is greater than the first increased RC distance.

[0031] Option 18. The motor vehicle according to Option 17, wherein the vehicle controller is further programmed to: Determine that the VLA sensor data indicates that the current VLA of the motor vehicle is less than the predetermined VLA threshold, and determine that the DTR data indicates that the current vehicle speed is less than the predetermined speed threshold; and In response to the current VLA being less than the predefined VLA threshold and the current vehicle speed being less than the predefined speed threshold, the electric servo motor is commanded to drive the BSA component, thereby changing the operating gap to a third increased RC distance, the third increased RC distance being greater than the first increased RC distance and the second increased RC distance.

[0032] Option 19. The motor vehicle according to Option 18, wherein the vehicle controller is further programmed to: Receive steering wheel angle (SWA) sensor data from the steering wheel angle sensor of the motor vehicle; and The SWA sensor data indicates that the current SWA of the steering wheel is less than a predetermined SWA threshold, wherein, in further response to the current SWA of the steering wheel being less than the predetermined SWA threshold, the servo motor is commanded to change the operating clearance to the third increased RC distance.

[0033] Option 20. The motor vehicle according to Option 15, wherein the vehicle controller is further programmed to determine, by the ADAS sensor data and the DTR data, that a braking request has not been received from the driver or ADAS control module of the motor vehicle, wherein in response to the absence of the braking request, it is determined whether the acceleration torque request has been received.

[0034] The foregoing summary does not represent every embodiment or aspect of this disclosure. Rather, it provides only a summary of some of the novel ideas and features set forth herein. The foregoing features and advantages, as well as other features and accompanying advantages of this disclosure, will become apparent from the detailed embodiments shown below for carrying out the present disclosure, when taken in conjunction with the appended drawings and claims. Furthermore, this disclosure expressly includes any and all combinations and sub-combinations of the elements and features presented above and below. Attached Figure Description

[0035] Figure 1 This is a partial schematic side view of a representative motor vehicle having a friction braking system with drive-by-wire for defining active braking resistance control and a network of controllers, sensors, and communication devices in the vehicle, according to various aspects of this disclosure.

[0036] Figure 2 This is a perspective view showing a representative electromechanical braking (EMB) unit, and various aspects of this disclosure can be put into practice.

[0037] Figure 3 This is a flowchart illustrating a representative braking system control protocol for actively mitigating braking resistance in BBW vehicle braking systems, based on various aspects of this disclosure. It may correspond to non-instantaneous, memory-stored instructions that can be executed by a resident or remote processor, control module, programmable logic device, central controller, or other integrated circuit (IC) device or network of processors / controllers / modules / devices, etc.

[0038] This disclosure is verifiable with respect to various modifications and alternatives, and some representative embodiments of this disclosure are illustrated by way of example in the accompanying drawings and will be described in detail herein. However, it should be understood that the novel aspects of this disclosure are not limited to the specific forms shown in the foregoing drawings. Rather, this disclosure covers all modifications, equivalents, combinations, arrangements, groups, and alternatives that fall within (e.g., encompassed by the appended claims) the scope of this disclosure. Detailed Implementation

[0039] This disclosure allows for many different forms of embodiments. Representative embodiments of this disclosure are illustrated in the accompanying drawings and will be described in detail herein as examples of the principles of the disclosure rather than as limitations on the broad aspects of the disclosure. To this extent, elements and limitations described, for example, in the abstract, technical field, summary of the invention, description of the drawings, and detailed description sections but not expressly set forth in the claims should not be incorporated into the claims individually or collectively by implication, inference, or otherwise. Furthermore, the statements “first,” “second,” “third,” etc., in the specification or claims are not inherently used to establish continuous or numerical limitations; unless specifically stated otherwise, these designations may be used to readily refer to similar features in the specification and drawings and to distinguish between similar elements in the claims.

[0040] For the purposes of this disclosure, unless expressly denied: singular forms include plural forms, and vice versa (e.g., the indefinite articles “a” and “one” should be interpreted essentially as “one or more”); the words “and” and “or” should be both conjunction and disjunction; the words “any” and “all” should both mean “any and all”; and the words “including,” “contains,” “including,” “having,” and similar words should each mean “including but not limited to.” Furthermore, approximate words such as “approximately,” “almost,” “substantially,” “basically,” “approximately,” and similar words may be used herein to represent, for example, “in, near, or almost in,” or “within 0-5% of,” or “within acceptable manufacturing tolerances,” or any logical combination thereof. Finally, directional adjectives and adverbs, such as hem, stern, inside, outside, starboard, port, vertical, horizontal, up, down, forward, aft, left, right, etc., may be relative to the motor vehicle, for example, the forward direction of travel of the motor vehicle when it is oriented operationally on a horizontal driving surface.

[0041] Referring now to the accompanying drawings, where similar reference numerals are used throughout the views to indicate similar features, in Figure 1The illustration depicts a representative motor vehicle, basically designated 10 and depicted herein as a car-style electric vehicle for the purposes of discussion. The illustrated vehicle 10 (also referred to herein simply as a "motor vehicle" or "vehicle") is merely an example application utilizing which novel aspects of this disclosure can be practiced. In the same context, the embodiments presented in the accompanying drawings that incorporate the present concept into specific EBM braking system architectures should also be understood as non-limiting implementations of the features of the disclosure. Thus, it should be understood that novel aspects of this disclosure can be implemented for other BBW braking system architectures and can be incorporated into any logically related type of motor vehicle. Furthermore, only selected parts of the motor vehicle and vehicle braking system are illustrated and described in detail herein. Nevertheless, the vehicles and braking systems discussed below may include a number of additional and alternative features, as well as other available peripheral hardware, for performing the various methods and functions of this disclosure.

[0042] Figure 1 The representative vehicle 10 is initially equipped with a vehicle telecommunications and information (“telematics processing”) unit 14, which wirelessly communicates with a remotely located cloud computing hosting service 24 (e.g., ONSTAR®) via, for example, a cellular network, satellite service, wirelessly supported modem, etc. Figure 1 Some of the other vehicle hardware components 16 in the basic illustration include (as a non-limiting example) an electronic video display device 18, a microphone 28, a speaker 30, and various user input controls 32 (e.g., pedals, buttons, knobs, switches, touchpads, touchscreens, etc.). These hardware components 16 partially function as a human-machine interface (HMI), enabling the user to communicate with the telematics unit 14 and other components residing in or away from the vehicle 10. The microphone 28, for example, provides the occupant with verbal commands; the vehicle 10 may be equipped with an embedded sound processing unit with audio filtering, editing, and analysis modules. Conversely, the speaker 30 provides audible output to the vehicle occupant and may be either a separate speaker dedicated to the telematics unit 14 or a component of the in-cabin audio system 22. The audio system 22 is connected to a network connection interface 34 and an audio bus 20 to receive analog and digital information via one or more speaker components and interpret it as sound.

[0043] The telematics unit 14 is communicatively connected to a network interface 34, suitable examples of which include a twisted-pair / fiber Ethernet switch, a parallel / serial communication bus, a local area network (LAN) interface, a controller area network (CAN) interface, and the like. The network interface 34 enables the vehicle hardware 16 to send and receive signals with each other and with various onboard and offboard systems of the vehicle body 12. This allows the vehicle 10 to perform various vehicle functions, such as regulating powertrain output, activating friction braking and regenerative braking systems, controlling vehicle steering, and other automated functions. For example, the telematics unit 14 can exchange signals with the following: the powertrain control module (PCM) 52, the advanced driver assistance system (ADAS) module 54, the brake system control module (BSCM) 56, the body control module (BCM) 58, the sensor system interface module (SSIM) 60, and various other vehicle ECUs, such as the engine control module (ECM), motor control module (MCM), transmission control module (TCM), sensing and diagnostic module (SDM), steering control module (SCM), etc.

[0044] Continue to refer to Figure 1 The telematics unit 14 is an in-vehicle computing device, a hybrid of both independent and communication-within-network devices. This telematics unit 14 may consist essentially of one or more processors 40, each of which may be embodied as a discrete microprocessor, an application-specific integrated circuit (ASIC), or a dedicated control module. The vehicle 10 may provide centralized vehicle control via a central processing unit (CPU) 36, operatively coupled to a real-time clock (RTC) 42 and one or more electronic storage devices 38, each of which may take the form of a CD-ROM, disk, IC device, solid-state drive (SSD) memory, hard disk drive (HDD) memory, phase-change memory, flash memory, semiconductor memory (e.g., various types of RAM or ROM), etc.

[0045] Long-range communication (LRC) capability for remote, non-vehicle-mounted devices can be provided via one or more or all of a cellular chipset / component, a navigation and location chipset / component (e.g., a Global Positioning System (GPS) transceiver), a wireless modem, or a mobile hotspot, all collectively represented by 44. Near-range wireless connectivity can be provided via a short-range communication (SRC) device 46 (e.g., a BLUETOOTH® unit or a Near Field Communication (NFC) transceiver), a dedicated short-range communication (DSRC) component 48, and / or a dual RF antenna 50. The communication devices described above can define data exchange as a periodic broadcast portion of a vehicle-to-vehicle (V2V) communication system or a vehicle-to-everything (V2X) communication system (e.g., vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), vehicle-to-device (V2D), vehicle-to-cloud (V2C), etc.).

[0046] CPU 36 receives sensor data from one or more sensing devices, such as photodetectors, radar, lidar, ultrasonic, optical, infrared, or other suitable technologies, including short-range communication technologies (e.g., DSRC) or ultra-wideband (UWB) radio technologies, to perform controller-automated driving (AV / ADAS) operations or vehicle navigation services. According to the illustrated example, vehicle 10 may be equipped with one or more digital cameras 62, one or more range sensors 64, one or more vehicle speed sensors 66, one or more vehicle dynamic sensors 68, and any necessary hardware and software for filtering, classifying, fusing, and analyzing the unprocessed sensor data. The type, location, number, and interoperability of the sensor array distribution in the vehicle can be individually or collectively adapted to the given vehicle platform to achieve the desired level of automated vehicle operation.

[0047] To propel the vehicle 10, the vehicle's power system is operable to generate traction torque and transmit it to one or more of the vehicle's drive wheels 26. The power system is activated by an electric traction motor (M) 78. Figure 1The battery pack 70 is operatively connected to a rechargeable energy storage system (RESS), which may essentially be a chassis-mounted traction battery pack 70. The traction battery pack 70 generally consists of one or more battery modules 72, each containing a set of battery cells 74, such as pouch, prismatic, or cylindrical lithium-, zinc-, nickel-, or silicone-based battery cells. One or more prime movers, such as a traction motor / engine (M) unit 78, draw power from the battery pack 70 and optionally deliver power to it. A power inverter module (PIM) 80 electrically connects the battery pack 70 to the motor 78 and regulates the current transfer between them. The battery pack 70 may include integrated electronics, such as a wirelessly supported battery cell monitoring unit (CMU) 76, which enables module-level management, battery cell sensing, etc.

[0048] Figure 2 The image shown is for motor vehicles (such as...) Figure 1 Non-limiting example of an electromechanical brake (EMB) disc brake unit 100 of a BBW vehicle braking system for a car 10). Figure 2 The EMB disc brake unit 100 basically consists of a disc-shaped brake rotor 102 and a floating brake caliper assembly 104. The disc-shaped brake rotor 102 is mounted to the hub of a wheel corner assembly (not shown), for example, via threaded studs and matching flange nuts. The floating brake caliper assembly 104 is mounted to the steering knuckle of the corner assembly, for example, via threaded bolts. The tire and wheel unit (not shown) are secured to the hub of the corner assembly with a circular configuration of flange nuts, such that the tire, wheel, hub, and rotor 102 all rotate simultaneously with each other. The brake caliper assembly 104 includes a rigid and protective caliper housing 108 that spans the brake rotor 102 (representing "rotating braking element") and carries a brake piston 106 for operatively engaging with a pair of inner and outer brake pads 110A and 110B (representing "friction braking elements"), respectively. The caliper housing 108 is movably mounted to the caliper mounting bracket 114 via a locking pin 116 and a matching hexagonal head bolt 118, allowing the caliper assembly 104 to "float" on the rotor 102. Although described herein as a single-piston, floating caliper disc braking design, it is conceivable that the EMB unit 100 can adopt any suitable friction braking configuration, including multi-piston configurations, opposing piston caliper designs, drum braking systems, etc.

[0049] During operation of the EMB unit 100, the brake piston 106 reciprocates within the caliper housing 108 (e.g., Figure 2The brake piston 106 shifts diagonally to the right and left to apply compressive force to the opposing brake pads 110A and 110B. For floating type caliper designs, the brake piston 106 first pushes against the brake pad 112 (which is adjacent to the backing plate of the inner brake pad 110A) until the pad 110A is pressed into the inner surface of the brake rotor 102. The continuous build-up of pressure applied to and through the now stationary piston 106 forces the caliper housing 108 to slide on the mounting bracket 114 (e.g., in...). Figure 2 (Sliding to the left). This causes the caliper housing 108 to pull the outer brake pad 110B against the outer surface of the brake rotor 102, so that the rotor 102 is now frictionally engaged with both the inner and outer brake pads 110A and 110B and is clamped between them. Activation of the brake piston 106 in this manner frictionally engages the friction materials of the two brake pads 110A and 110B against opposite sides of the rotor 102 during a braking event. This frictional engagement converts the kinetic energy of the vehicle wheel unit into the thermal energy of the EMB unit 100, which in turn slows down / stops the rotation of the rotor and wheel.

[0050] Mounted to the inner end of the caliper housing 108 is a motor-driven ball screw actuator (BSA) assembly 120, which is operable to selectively influence the activation and deactivation of the brake piston 106 of the EMB unit. Figure 2 The BSA assembly 120 employs a rigid and protective BSA outer housing 122, which contains an electric servo motor 124, a belt-driven transmission 126, and a ball screw actuator 128. The work of the electric servo motor 124 (representing the "brake motor") can be controlled by the braking system electronic control unit (e.g., ...). Figure 1 The BSCM56 manages the transmission of torque from the drive sleeve 130 mounted on the motor shaft through the toothed drive belt 132 to the driven pulley 134 of the belt drive transmission 126. Rotational force is transmitted from the pulley 134 through the toothed drive shaft 136 to the complementary puncture type reduction gear 138 (representing "brake actuator") of the ball screw actuator 128. The rotation of the reduction gear 138 affects the threaded shaft 140 (e.g., in...). Figure 2 A linear translation (from left to right) causes the end of the threaded shaft 140 to press and translate against the brake piston 106. The disengagement of the shaft 140 and the piston 106 can be affected by reversing the rotational output of the servo motor 124.

[0051] When operating a friction braking system, such as the BBW EMB vehicle braking system, the braking hardware may experience a "brake resistance" condition, in which the brake pads fail to fully disengage from the brake rotor when the brake pedal is released or the deceleration torque requirement is otherwise not continued. A key factor affecting the severity and duration of brake resistance events is the part-to-part clearance (or "running clearance") between the brake pads and brake rotor when braking is not applied. For example, a large running clearance tends to reduce brake resistance but can also lead to a higher system response time. On the other hand, a small running clearance can alleviate system response time but can also lead to increased brake resistance. Therefore, when the system calibration settings are obtained, the default running clearance can be set to an optimized value that minimizes brake resistance while limiting any accompanying increase in system response time. The following discusses a closed-loop feedback control system and method for mitigating brake resistance in the BBW friction braking system by dynamically adjusting the running clearance to an optimized RC value (each tailored to the specific operating state of the tested "master" vehicle). Active brake resistance control can be achieved using precise piston extension and retraction movement controlled by an EMB motor.

[0052] As the primary vehicle travels in the forward direction, the stationary BSCM / ECU can systematically monitor the real-time accelerator pedal position; if the pedal is depressed, the BSCM / ECU can infer that the driver does not intend to apply vehicle braking (i.e., "no intention to brake"). In this case, the brake piston can be moved away from the brake rotor to increase operating clearance and reduce braking resistance. Similarly, the BSCM / ECU can monitor acceleration requests during adaptive cruise control (ACC): if acceleration is requested, the piston can move backward to ensure sufficient operating clearance and reduce braking resistance. Once the acceleration request (whether by the driver or ADAS) ceases, the piston can return to its optimized default position to maintain a stable operating clearance that does not negatively impact the braking system's response time. Upon detection of a forward impact warning or other ADAS warning event that triggers AEB, the piston can move towards the brake rotor to reduce RC and ensure faster reaction time, thereby reducing AEB braking distance and improving AEB braking performance. Real-time vehicle speed and vehicle turning can also be actively monitored by the BSCM / ECU; if the primary vehicle is traveling at a relatively low speed or turning, RC can be increased to ensure that no braking resistance occurs in those situations.

[0053] Accompanying benefits of at least some of the disclosed concepts include intelligent vehicle braking systems and control logic that specify improved braking resistance mitigation by actively and automatically adjusting the operating clearance for selected driving conditions without affecting braking system response time. Instead of using conventional hydraulic pressure (which may not enable precise piston positioning), the vehicle's BSCM / ECU can dynamically respond to alter vehicle operating conditions by selectively changing the operating clearance between the brake pads and rotors through a bidirectional electric motor integrated into each EMB caliper assembly, pushing or pulling each caliper piston. The braking system ECU can actively change the operating clearance based on driver and ADAS feedback communicated with the TBW accelerator pedal, SBW steering wheel, or ACP / ACC / BSD / AEB modules. It is envisioned that the RC can change synchronously for all EMB units in a coordinated manner, or, if desired, for only one or some of the EMB units.

[0054] The operating clearance between the pad and the rotor can be actively adapted to any one of a plurality of predefined RC values, each associated with a corresponding setting for the vehicle's operating conditions. By way of a non-limiting example, braking resistance performance can be optimized by actively adjusting RC according to the vehicle's operating conditions as follows: (1) Typically: Default operating clearance, which balances braking resistance and braking system response time (e.g. RC def = Approximately 0.3 millimeters (mm); (2) Level 1: A small increase in running clearance to achieve better drag performance during acceleration (e.g., backward calibration #1: RC L1 = Approximately 0.4mm); (3) Level 2: Moderate increase in running clearance to improve drag performance during cornering maneuvers with increased lateral forces (e.g., rearward calibration #2: RC L2 = Approximately 0.45mm); (4) Level 3: A large increase in running clearance to obtain better drag performance at low vehicle speeds (e.g., backcalibration #3: RC L3 =approximately 0.5mm); and (5) Level 0: Reduces the running gap compared to the normal setting to provide better system response time (e.g., forward calibration #3: RC F1 = Approximately 0.2mm).

[0055] In general, the operating clearances can be fixed in order from smallest to largest (Level 0 < Normal < Level 1 < Level 2 < Level 3) and can be calibrated according to predefined vehicle characteristics. It should be understood that the vehicle braking system can be larger or smaller than the five predefined operating clearances mentioned above (e.g., additional reduced RC values ​​can be added for various predicted braking events). Furthermore, the specific RC values ​​presented above are provided for illustrative purposes only and are therefore non-limiting in nature. It is conceivable that, instead of selecting from a fixed set of predefined RC values, the operating clearances of the BBW vehicle braking system can be continuously varied within a predefined RC range.

[0056] Automatic operating clearance adjustment can be achieved through precise piston contraction control of an independent EMB braking unit during regular vehicle operation. The braking system can predict the driver's lack of immediate braking intention by monitoring accelerator pedal use. For example, the braking system BSCM / ECU can communicate with the ECM, which tracks the accelerator pedal position; once it confirms that accelerator is depressurized, the system can command an increase (e.g., level 1) in the operating clearance between the brake pedal and the brake rotor. The vehicle braking system can simultaneously determine the absence of ACC braking intention from the ACC system's output acceleration request signal. For example, the braking system BSCM / ECU can communicate with the ACP module controlling ACC and can command an increase in the operating clearance between the brake pedal and the rotor once it confirms that ACC maintains or increases vehicle speed and therefore does not currently require activation of the braking system.

[0057] Operating clearance can be further increased during vehicle acceleration and cornering maneuvers to provide additional improvement in braking resistance performance. The braking system BSCM / ECU can communicate with the electric power steering (EPS) module (which is responsible for monitoring the vehicle's dynamic state) to detect the onset of cornering maneuvers, as the brake rotors expect greater braking resistance during cornering due to lateral force deflection. The braking system can respond by setting a larger RC (e.g., level 2) to improve drag performance until the vehicle completes the turn; at that point, RC can be reset to its default value (e.g., normally). The system can set the maximum operating clearance during low-speed driving. The system can ensure a smaller operating clearance when the vehicle is driving in reverse, operating in low visibility or low-mu driving conditions, or driving in traffic. Reduced operating clearance can be implemented for various ADAS warning events, such as lane departure, crossing traffic, blind spot warnings, etc., to optimize response time and reduce braking distance.

[0058] Next reference Figure 3 The flowchart, based on various aspects of this disclosure, is described in 200 basic terms for motor vehicles (e.g., Figure 1 The car 10) is used for actively controlling friction braking systems (such as those with...) Figure 2 Methods or control protocols for improving braking resistance of the BBW braking system (EMB disc brake unit 100). Figure 3 Some or all of the operations shown in the diagram and described in detail below may represent algorithms corresponding to instructions executable by a non-transient processor, which may be stored, for example, in primary or secondary or remote memory (e.g., Figure 1 Resident memory 38 and / or remote cloud host service 24 database). These instructions may be, for example, generated by a resident or remote microprocessor, central controller, dedicated control module, programmable logic device, or other module or device of a processor / controller / module / device, or network (e.g., Figure 1 The CPU36 and / or cloud host service 24 server-type calculator terminal) are used to execute, so as to perform any or all of the functions described above and below in connection with the disclosed concept. It should be understood that the execution order of the operation blocks shown can be changed, additional operation blocks can be added, and some of the operations described herein can be modified, combined, or eliminated.

[0059] Method 200 can be used Figure 3 Beginning at terminal block 201, the method contains memory-stored, computer-readable instructions for initializing a friction braking system's operational clearance optimization protocol. This routine can be initialized in real-time, near real-time, continuously, systematically, intermittently, and / or at predetermined time intervals (e.g., every 10 or 100 milliseconds during operation of the motor vehicle 10). Alternatively, terminal block 201 can be initialized in response to user command prompts (e.g., via telematics input controls 28, 32), vehicle controller prompts (e.g., from CPU 36), or broadcast prompts received from a centralized BO vehicle service system (e.g., from cloud host service 24). By way of a non-limiting example, method 200 can be automatically initialized during a key start event, where the driver, owner, possessor, or other authorized operator of the vehicle 10 (collectively referred to as the "user") starts the vehicle's powertrain, for example, by pressing the ignition start button, or by shifting gears, for example, by turning the PRNDL shift knob inside the passenger compartment 11, placing the vehicle in driving (D) mode. Figure 3 Once some or all of the control operations presented in the process are completed, method 200 can proceed to the end terminal block 229 and temporarily terminate, or optionally it can cycle back to terminal block 201 and operate in a continuous loop. Terminal block 229 can be automatically triggered in response to a key off event, or in response to the user shifting the powertrain to neutral or parking mode, in which case the user turns off the main vehicle.

[0060] Method 200 can proceed from terminal block 201 to default RC preparation block 203 and set the main vehicle's friction braking system to the default caliper position. By way of example and not limitation, the parked vehicle BSCM 56 can respond to a key start event and / or vehicle shifting to driving mode by accessing the parked memory device 38 to retrieve the normal RC value from it. The BSCM 56 can also broadcast command signals to each of the EMB servo motors 124 to drive the ball screw actuator 128 to shift the threaded shaft 140 and set the brake piston 106 to the normal RC position. Conversely, the BBW vehicle braking system may have already set the brake piston 106 to the normal RC position (e.g., when the main vehicle is shifted to park (P) mode); in this example, preparation block 203 may be optional, or can be omitted from method 200 if desired.

[0061] At this critical juncture, method 200 can begin monitoring operator input and ADAS feedback to track torque request commands from the driver and vehicle. For example, driver torque request data input block 205 may include aggregated DTR data indicating real-time torque commands from the driver, while vehicle torque request data input block 207 may include aggregated ADAS data indicating real-time torque commands and driving alerts from the ADAS system. As noted above, DTR data can be generated by one or more driver input devices, including accelerator pedal position sensors, parking ECMs, steering wheel-mounted cruise control buttons, wheel speed sensors, etc. In the same context, ADAS data can be generated by one or more vehicle control modules, such as ACP, ACC, BSD, and AEB modules, and by one or more sensing devices in a sensor array on the vehicle, such as forward-facing vehicle cameras, forward-facing long-range radar sensors, forward-facing mid-range lidar sensors, etc. The collected data can be filtered, preprocessed, fused, stored, and analyzed to… Figure 3 The driver / ADAS subroutine 209 obtains the operator's and vehicle's intent.

[0062] When tracking driver and vehicle input, method 200 can execute ADAS warning decision block 211 to determine whether an ADAS warning event has been detected by the primary vehicle. For example, the braking system BSCM / ECU can communicate with ADAS module 54 and SSIM 60 to determine whether a forward impact event has been detected and the corresponding forward impact warning (e.g., via...). Figure 1Whether the remote information processing unit 14) outputs to the driver. If an ADAS warning event is detected (block 211 = yes), method 200 can responsively execute RC forward (L0) processing block 213 and command each brake motor 124 to drive the brake actuator 120 and piston 106, thereby reducing the operating clearance between brake pads 110A, 110B and brake rotor 102 to a reduced RC distance (e.g., forward calibration #1). RC F1 This will help reduce system response time when the vehicle driver needs to react to detected ADAS events. After an ADAS warning event is detected, the vehicle's BSCM / ECU can evaluate the new ADAS data to determine whether the ADAS warning event is no longer being detected; once it is confirmed that the ADAS warning event is no longer being detected, the BSCM / ECU can responsively command the BBW system's brake motor to reposition the brake piston and pad to reset the operating clearance to the default (normal) RC.

[0063] Continue to refer to Figure 3 Method 200 can respond to the absence or cessation of detection of ADAS warning events (block 211 = No) by executing acceleration request decision block 215 to determine whether an acceleration request has been received from the driver or ADAS system to increase the speed of the primary vehicle. The absence of an acceleration torque request may suggest that the driver or vehicle may be preparing to activate the vehicle's braking system, and thus, the running clearance should not increase at that time. As a result, if no acceleration torque request is detected (block 215 = No), method 200 can responsively cycle back to processing block 203 and either reset the primary vehicle's friction braking system to the default (normal) caliper position (e.g., if RC was previously changed) or hold the braking system in the default position (e.g., if RC was not previously changed). For at least some applications, if any pressure is applied to the accelerator pedal, resulting in a measurable amount of pedal movement, regardless of whether the driver is requesting acceleration of the primary vehicle (e.g., the driver is maintaining the current vehicle speed), decision block 215 can return a positive (Yes) result.

[0064] Upon confirming that the driver / vehicle is currently requesting vehicle acceleration and therefore does not expect to activate the vehicle braking system (block 215 = Yes), method 200 can responsively execute low-speed decision block 217 to determine whether the real-time speed of the primary vehicle is less than a predefined speed threshold (e.g., 10 kph). If the primary vehicle is currently operating at a low vehicle speed (block 217 = Yes), method 200 can responsively execute RC backward (L3) processing block 219 and command each BBW brake motor 124 to retract the brake actuator 120 and piston 106, thereby increasing the operating clearance by a large (third) increased RC distance (e.g., backward calibration #3). RC L3 Although not required by the driver, the braking system BSCM / ECU can confirm the lack of required braking torque by verifying that the brake pedal is not currently being pressed down by the driver.

[0065] Figure 3 Method 200 can infer that the real-time vehicle speed exceeds a predefined speed threshold, and therefore the primary vehicle does not operate at a low vehicle speed (block 217 = No). In this case, method 200 can respond by executing vehicle turning decision block 221 to determine whether the primary vehicle is currently performing a turning maneuver. Returning to... Figure 1 For example, the vehicle BSCM 56 can communicate with the vehicle dynamics sensor 68 (e.g., an inertial measurement unit (IMU) with a six-axis accelerometer and an integrated gyroscope) via the SSIM 60 to retrieve real-time vehicle lateral acceleration (VLA) data for the primary vehicle. In this example, the vehicle BSCM 56 can filter, preprocess, store, and evaluate the VLA sensor data to determine whether the real-time lateral acceleration of the primary vehicle exceeds a predefined VLA threshold (e.g., approximately 0.2g's). To confirm that the primary vehicle is actually performing a turning maneuver, rather than simply modifying the vehicle's forward driving angle, the BSCM 56 can communicate with the stationary SCM to retrieve steering wheel angle (SWA) sensor data from the SBW steering wheel angle sensor. Once retrieved, the BSCM 56 can evaluate the SWA data to confirm that the real-time SWA of the primary vehicle's steering wheel is greater than a predefined SWA threshold (e.g., approximately 235 degrees (°)). If the main vehicle is performing a turning maneuver (block 221 = yes), method 200 can responsively execute RC backward (L2) processing block 223 and command one or more of the BBW brake motors 124 to retract the brake actuator 120 and piston 106, thereby increasing the operating clearance to a moderately (second) increased RC distance (e.g., backward calibration #2). RC L2 ).

[0066] After confirming that the main vehicle is not performing turning maneuvers (block 221 = No), Figure 2 Method 200 can responsively execute the RC backward (L1) processing block 225 and command some or all of the BBW brake motor 124 to retract the brake actuator 120 and piston 106, thereby increasing the operating clearance by a small (first) increased RC distance (e.g., backward calibration #1). RC L1 After completing any one of the operation gap calibrations at processing blocks 219, 223, and 225, method 200 can proceed to cycle out of decision block 227 and determine whether the vehicle is still traveling in the forward direction. If the vehicle has come to a stop and shifted into park (P) mode, or has been turned off (block 227 = No), method 200 can responsively cycle back to end terminal block 229 and temporarily terminate. On the other hand, if the main vehicle is still in drive (D) mode and traveling in the forward direction (block 227 = Yes), method 200 can responsively cycle back to decision block 215 to determine whether the driver and ADAS system have input acceleration torque requirements for the main vehicle.

[0067] In some embodiments, aspects of this disclosure may be implemented by a computer-executable program of instructions, such as a program module, which generally refers to a software application or application executed by any of the controllers or variations thereof described herein. In a non-limiting example, the software may include routines, programs, objects, components, and data structures that perform a particular task or implement a particular data type. The software may form an interface to allow the computer to react according to a source of input. The software may also cooperate with other code segments to initiate various tasks in response to data received in conjunction with a source of received data. The software may be stored on any of a variety of memory media, such as CD-ROMs, disks, and semiconductor memories (e.g., various types of RAM or ROM).

[0068] Furthermore, aspects of this disclosure can be practiced using various computer systems and computer network configurations, including multiprocessor systems, microprocessor-based or consumer-programmable electronic devices, microcomputers, mainframe computers, or the like. Additionally, aspects of this disclosure can be practiced in distributed computing environments, where tasks are performed via resident and remote processing devices linked through communication networks. In distributed computing environments, program modules can reside on both local and remote computer storage media, including computer storage devices. Therefore, aspects of this disclosure can thus be implemented in computer systems or other processing systems in combination with various hardware, software, or combinations thereof.

[0069] Any of the methods described herein may include machine-readable instructions to be executed by: (a) a processor, (b) a controller, and / or (c) any other suitable processing means. Any algorithm, software, control logic, protocol, or method disclosed herein may be embodied as software stored on a tangible medium, such as flash memory, solid-state drive (SSD) memory, hard disk drive (HDD) memory, CD-ROM, digital video optical disc (DVD), or other storage device. The entire algorithm, control logic, protocol, or method, and / or portions thereof, may alternatively be executed by means other than a controller, and / or embedded in firmware or dedicated hardware in an available manner (e.g., implemented via application-specific integrated circuits (ASICs), programmable logic devices (PLDs), field-programmable logic devices (FPLDs), discrete logic, etc.). Furthermore, although specific algorithms may be described with reference to the flowcharts and / or workflow diagrams depicted herein, many other methods for implementing the example machine-readable instructions may be used alternatively.

[0070] Various aspects of this disclosure have been described in detail with reference to the illustrated embodiments; however, those skilled in the art will recognize that many modifications can be made thereto without departing from the scope of this disclosure. This disclosure is not limited to the precise structures and components disclosed herein; any and all modifications, alterations, and variations that are apparent from the foregoing description are within the scope of this disclosure as defined by the appended claims. Furthermore, this concept explicitly includes any and all combinations and sub-combinations of the preceding elements and features.

Claims

1. A method of operating a motor vehicle having a brake-by-wire (BBW) braking system, the BBW braking system including a brake motor configured to drive a brake actuator to press a friction brake element against a rotating brake element, the method comprising: The vehicle controller receives vehicle dynamic data indicating that the motor vehicle is traveling in the forward direction; In response to the motor vehicle traveling in the forward direction, the vehicle controller receives advanced driver assistance system (ADAS) data and drive torque requirement (DTR) data for the motor vehicle. The vehicle controller determines whether the ADAS data indicates that an ADAS warning event has been detected, and whether the DTR data indicates that an acceleration torque request has been received to accelerate the motor vehicle. as well as The brake motor is commanded to drive the brake actuator, thereby changing the operating clearance (RC) between the friction brake element and the rotating brake element to a reduced RC distance in response to the detection of the ADAS warning event, or to a first increased RC distance in response to receiving the acceleration torque request to accelerate the motor vehicle.

2. The method according to claim 1, further comprising: The vehicle controller determines that the ADAS data indicates that the ADAS warning event was not detected, and determines that the DTR data indicates that the acceleration torque request was received to accelerate the motor vehicle. as well as In response to the absence of the ADAS warning event and the receipt of the acceleration torque request, the vehicle controller receives vehicle lateral acceleration (VLA) sensor data from the multi-axis accelerometer of the motor vehicle.

3. The method of claim 2, further comprising: The vehicle controller determines whether the VLA sensor data indicates that the current VLA of the motor vehicle exceeds a predefined VLA threshold. as well as In response to the current VLA exceeding the predefined VLA threshold, the brake motor is commanded to drive the brake actuator, thereby changing the operating gap to a second increased RC distance, the second increased RC distance being greater than the first increased RC distance.

4. The method of claim 3, further comprising: The vehicle controller determines, via the VLA sensor data, that the current VLA of the motor vehicle is less than the predetermined VLA threshold, and determines, via the DTR data, that the current vehicle speed is less than the predetermined speed threshold; as well as In response to the current VLA being less than the predetermined VLA threshold and the current vehicle speed being less than the predetermined speed threshold, the brake motor is commanded to drive the brake actuator, thereby changing the operating clearance to a third increased RC distance, the third increased RC distance being greater than the first increased RC distance and the second increased RC distance.

5. The method of claim 4, further comprising: The vehicle controller receives steering wheel angle (SWA) sensor data from the steering wheel angle sensor of the motor vehicle. as well as The vehicle controller determines, via the vehicle controller, that the SWA sensor data indicates that the current SWA of the steering wheel is less than a predetermined SWA threshold, wherein, in further response to the current SWA of the steering wheel being less than the predetermined SWA threshold, the brake motor is commanded to change the operating clearance to the third increased RC distance.

6. The method of claim 1, further comprising: Before changing the operating gap, the vehicle controller receives vehicle ignition data instructing the motor vehicle to start. as well as In response to the start of the motor vehicle, the brake motor is commanded to drive the brake actuator, thereby setting the operating clearance to the default RC distance.

7. The method of claim 1, further comprising: After changing the RC to the first increased RC distance, the vehicle controller determines whether the motor vehicle is still traveling in the forward direction; In response to the determination that the motor vehicle is still traveling in the forward direction, the vehicle controller determines whether a new acceleration torque request should be received to accelerate the motor vehicle. as well as In response to the failure to receive the new acceleration torque request, the brake motor is commanded to drive the brake actuator, thereby setting the operating clearance to the default RC distance.

8. The method of claim 1, wherein the acceleration torque requirement is received from the driver via a driver input device and / or from the ADAS control module of the ADAS system.

9. A non-transitory computer-readable medium storing instructions executable by a vehicle controller of a motor vehicle having a brake-by-wire (BBW) braking system, the BBW braking system including a brake motor configured to drive a brake actuator to press a friction brake element against a rotating brake element, the instructions, when executed, causing the vehicle controller to perform an operation including: Receive vehicle dynamic data indicating that the motor vehicle is traveling in the forward direction; In response to the motor vehicle traveling in the forward direction, it receives advanced driver assistance system (ADAS) data and drive torque requirement (DTR) data; Determine whether the ADAS data indicates that an ADAS warning event has been detected, and whether the DTR data indicates that an acceleration torque request has been received to accelerate the motor vehicle; as well as The brake motor is commanded to drive the brake actuator, thereby changing the operating clearance (RC) between the friction brake element and the rotating brake element to a reduced RC distance in response to the detection of the ADAS warning event, or to a first increased RC distance in response to receiving the acceleration torque request to accelerate the motor vehicle.

10. A motorized vehicle, comprising: The vehicle itself; Multiple road wheels attached to the main body of the vehicle; A prime mover, which is attached to the vehicle body and configured to drive at least one of the road wheels, thereby propelling the motorized vehicle; A brake-by-wire (BBW) braking system, attached to the vehicle body and comprising a plurality of electromechanical brake (EMB) units, each EMB unit configured to slow down a corresponding one of the road wheels, each EMB unit including an electric servo motor configured to drive a ball screw actuator (BSA) assembly and thereby push a brake piston against a brake pad, such that the brake pad presses against a brake rotor, the brake rotor being mounted to rotate simultaneously with a corresponding one of the road wheels; as well as Vehicle controller, the vehicle controller being programmed to: Receive vehicle dynamic data indicating that the motor vehicle is traveling in the forward direction; In response to the motor vehicle traveling in the forward direction, the driver receives advanced driver assistance system (ADAS) sensor data from the vehicle sensor array and drive torque requirement (DTR) data from the driver input device. Determine whether the ADAS sensor data indicates that an ADAS warning event has been detected, and whether the DTR data indicates that an acceleration torque request has been received to accelerate the motor vehicle; as well as The electric servo motor is commanded to drive the BSA assembly, thereby changing the operating clearance (RC) between the brake pad and the brake rotor to a reduced RC distance in response to the detection of the ADAS warning event, or to a first increased RC distance in response to receiving the acceleration torque request to accelerate the motor vehicle.

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