Vehicle brake operation

Abstract

The present disclosure provides for "vehicle brake operation." A system, comprising a computer including a processor and a memory storing instructions executable by the processor for: actuating a vehicle brake in accordance with a prescribed brake torque; receiving a user input to exceed the prescribed brake torque; and actuating a brake fluid valve to obtain brake fluid pressure to maintain the prescribed brake torque.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle braking systems. Background Technology

[0002] Vehicles include brakes to slow and stop the vehicle. Brakes can output braking torque to slow the wheels. In autonomous vehicles, the vehicle user and the vehicle computer can provide input to actuate the brakes. Input from the vehicle user and the vehicle computer can increase the braking torque applied to the wheels. However, problems arise when both the vehicle user and the vehicle computer provide input to actuate the brakes. Summary of the Invention

[0003] A system includes a computer comprising a processor and a memory storing instructions executable by the processor for: actuating a vehicle brake according to a predetermined braking torque; receiving user input to exceed the predetermined braking torque; and actuating a brake fluid valve to obtain brake fluid pressure thereby maintaining the predetermined braking torque.

[0004] The instructions may also include instructions for actuating the brake fluid pump to obtain brake fluid pressure thereby maintaining a specified braking torque.

[0005] The instructions may also include instructions for recognizing user input based on data of at least one of vehicle acceleration, braking torque, and brake fluid pressure.

[0006] The instructions may also include instructions for actuating the brake fluid valve to connect the brake cylinder to the fluid reservoir.

[0007] The instructions may also include instructions for actuating the brake fluid valve to isolate the brake cylinder from the brake.

[0008] The instructions may also include instructions to actuate the brake fluid valve when the vehicle acceleration exceeds an acceleration threshold.

[0009] The instructions may also include instructions for actuating the brake valve in a periodic shutter mode to reduce the brake fluid pressure.

[0010] The instructions may also include instructions for performing the following: opening the brake fluid valve after receiving user input to the brake pedal; closing the brake fluid valve after a predetermined time period; determining the current brake fluid pressure; and opening the brake fluid valve to maintain a predetermined braking torque when the current brake fluid pressure is greater than a specified brake fluid pressure.

[0011] The instructions may also include instructions for recognizing user input to the brake pedal based on data collected from the brake pedal angle sensor.

[0012] A vehicle braking system includes: a brake pedal; a brake fluid pump; a brake fluid valve in communication with the brake pedal; means for actuating the brake fluid pump according to a predetermined braking torque; means for receiving a user input exceeding the predetermined braking torque; and means for actuating the brake fluid valve upon receiving the user input to obtain brake fluid pressure thereby maintaining the predetermined braking torque.

[0013] The system may also include means for recognizing user input based on data of at least one of vehicle acceleration, braking torque, and brake fluid pressure.

[0014] The system may also include means for actuating a brake fluid valve to connect the brake cylinder to a fluid reservoir.

[0015] The system may also include means for actuating a brake fluid valve to isolate the brake cylinder from the brake fluid pump.

[0016] The system may further include: means for opening the brake fluid valve after receiving user input to the brake pedal; means for closing the brake fluid valve after a predetermined time period; means for determining the current brake fluid pressure; and means for opening the brake fluid valve to output a predetermined braking torque when the current brake fluid pressure is greater than a specified brake fluid pressure.

[0017] One method includes: actuating a vehicle brake according to a specified braking torque; receiving user input to exceed the specified braking torque; and actuating a brake fluid valve to obtain brake fluid pressure to maintain the specified braking torque.

[0018] The method may also include actuating a brake fluid pump to obtain brake fluid pressure thereby maintaining a specified braking torque.

[0019] The method may also include identifying user input based on data of at least one of vehicle acceleration, braking torque, and brake fluid pressure.

[0020] The method may also include actuating a brake fluid valve to connect the brake cylinder to a fluid reservoir.

[0021] The method may also include actuating a brake fluid valve to isolate the brake cylinder from the brake.

[0022] The method may further include: opening the brake fluid valve after receiving user input to the brake pedal; closing the brake fluid valve after a predetermined time period; determining the current brake fluid pressure; and opening the brake fluid valve to output a predetermined braking torque when the current brake fluid pressure is greater than a specified brake fluid pressure.

[0023] A computer programmed to perform any of the above-described method steps is further disclosed. A vehicle including a computer is also further disclosed. A computer program product comprising a computer-readable medium storing instructions executable by a computer processor for performing any of the above-described method steps is also further disclosed.

[0024] In autonomous vehicles, the vehicle computer can operate the vehicle brakes without user input. However, when a user provides input to the brake pedal, the braking torque may exceed the prescribed braking torque determined by the computer. To mitigate the increased braking torque from user input, the computer can actuate one or more brake fluid valves to direct brake fluid into a fluid reservoir until a prescribed brake fluid pressure is reached to achieve the prescribed braking torque. Therefore, even when the user provides input to the brakes, the computer can actuate the brakes and provide full and / or partial control over them. Attached Figure Description

[0025] Figure 1 This is a block diagram of an exemplary system for braking a vehicle.

[0026] Figure 2 An exemplary brake is shown.

[0027] Figure 3 It shows the function of receiving input to the brake pedal. Figure 2 An example brake.

[0028] Figure 4 This is a block diagram of an exemplary process for braking a vehicle. Detailed Implementation

[0029] Figure 1 An exemplary system 100 for braking a vehicle 101 is shown. A computer 105 in the vehicle 101 is programmed to receive collected data 115 from one or more sensors 110. For example, the vehicle 101 data 115 may include the vehicle 101's position, data about the environment surrounding the vehicle, data about objects outside the vehicle (such as another vehicle), etc. The vehicle 101's position is typically provided in a conventional form, such as geographic coordinates, such as latitude and longitude coordinates obtained via a navigation system using a Global Positioning System (GPS). Further examples of data 115 may include measurements of the vehicle 101's systems and components, such as the vehicle 101's speed, vehicle 101's trajectory, etc.

[0030] Computer 105 is typically programmed for communication on a vehicle network 101, which includes, for example, a conventional vehicle 101 communication bus. Computer 105 can transmit and / or receive messages from various devices in vehicle 101, such as controllers, actuators, sensors, etc., including sensor 110, via networks, buses, and / or other wired or wireless mechanisms (e.g., wired or wireless local area networks in vehicle 101). Alternatively or additionally, where computer 105 actually comprises multiple devices, the vehicle network can be used for communication between the devices represented herein as computer 105. Furthermore, computer 105 can be programmed to communicate with network 125, as described below, which may include various wired and / or wireless networking technologies, such as cellular, Low power (BLE), wired and / or wireless packet networks, etc.

[0031] Data repository 106 can be of any type, such as a hard drive, solid-state drive, server, or any volatile or non-volatile media. Data repository 106 can store the collected data 115 transmitted from sensor 110.

[0032] Sensor 110 may include a variety of devices. For example, various controllers in vehicle 101 may operate as sensors 110 to provide data 115 via the network or bus of vehicle 101, such as data 115 related to vehicle speed, acceleration, position, subsystem and / or component status. Furthermore, other sensors 110 may include cameras, motion detectors, etc., i.e., sensors 110 used to provide data 115 to assess component position, assess road gradient, etc. Sensor 110 may also include, but is not limited to, short-range radar, long-range radar, lidar, and / or ultrasonic transducers.

[0033] The collected data 115 may include a variety of data collected in vehicle 101. Examples of the collected data 115 have been provided above, and in addition, data 115 is typically collected using one or more sensors 110, and may additionally include data calculated from the collected data in computer 105 and / or at server 130. Typically, the collected data 115 may include any data that can be acquired by sensors 110 and / or calculated from such data.

[0034] Vehicle 101 may include multiple vehicle components 120. In this context, each vehicle component 120 includes one or more hardware components adapted to perform mechanical functions or operations, such as moving vehicle 101, slowing or stopping vehicle 101, steering vehicle 101, etc. Non-limiting examples of components 120 include: propulsion components (which include, for example, internal combustion engines and / or electric motors), transmission components, steering components (e.g., which may include one or more of a steering wheel, steering rack, etc.), braking components (as described above), parking assist components, adaptive cruise control components, adaptive steering components, movable seats, etc.

[0035] When computer 105 operates vehicle 101, vehicle 101 is an "autonomous" vehicle 101. For the purposes of this disclosure, the term "autonomous vehicle" is used to refer to vehicle 101 operating in a fully autonomous mode. A fully autonomous mode is defined as a mode in which each of the vehicle 101's propulsion (typically via a powertrain including an electric motor and / or an internal combustion engine), braking, and steering is controlled by computer 105. A semi-autonomous mode is a mode in which at least one of the vehicle 101's propulsion (typically via a powertrain including an electric motor and / or an internal combustion engine), braking, and steering is at least partially controlled by computer 105 rather than a human operator. In a non-autonomous mode (i.e., manual mode), the propulsion, braking, and steering of vehicle 101 are controlled by a human operator.

[0036] System 100 may also include a network 125 connected to server 130 and data storage device 135. Computer 105 may also be programmed to communicate via network 125 with one or more remote sites, such as server 130, which may include data storage device 135. Network 125 represents one or more mechanisms through which vehicle computer 105 can communicate with remote server 130. Therefore, network 125 can be one or more of various wired or wireless communication mechanisms, including any desired combination of wired (e.g., cable and fiber optic) and / or wireless (e.g., cellular, wireless, satellite, microwave, and radio frequency) communication mechanisms, and any desired network topology (or multiple topologies when using multiple communication mechanisms). Exemplary communication networks include wireless communication networks that provide data communication services (e.g., using...). Low power (BLE), IEEE 802.11, vehicle-to-vehicle (V2V), such as Dedicated Short Range Communication (DSRC), local area network (LAN) and / or wide area network (WAN), the WAN including the Internet.

[0037] Figure 2An exemplary brake 120 in vehicle 101 is shown. Vehicle 101 includes a plurality of wheels 200. The wheels allow vehicle 101 to move along a road. A thruster 120 rotates the wheels 200, thereby propelling vehicle 101, and the brake 120 slows the rotation of the wheels 200, thereby slowing and stopping vehicle 101. The brake 120 may include brake pads 205 on at least one of the wheels 200, which generate friction on the wheel 200, thereby slowing the rotation of the wheel 200.

[0038] An exemplary brake 120 includes a brake pedal 210. The brake pedal 210 receives user input to actuate the brake 120. As described below, a user can depress the brake pedal 210 to slow and stop the vehicle 101. When the computer 105 operates the vehicle 101 in fully autonomous mode, the computer 105 can actuate the brake 120 without user input to the brake pedal 210. Therefore, when a user provides input to the brake pedal 210 and the vehicle 101 is in autonomous mode, the computer 105 can actuate portions of the brake 120 to take the user input into account.

[0039] An exemplary brake 120 includes a brake cylinder 215. The brake cylinder 215 is attached to a brake pedal 210. The brake cylinder includes brake fluid. When a user provides input to the brake pedal 210, the brake cylinder 215... Figure 2 The first position shown is moved to Figure 3 The second position is shown. Brake cylinder 215 includes piston 220 and spring 225. Piston 220 is connected to brake pedal 210. When the user depresses brake pedal 210, piston 220 causes spring 225 to coil, thereby pushing brake fluid from brake cylinder 215. When the user releases brake pedal 210, spring 225 unfolds, thereby pushing piston 220 and drawing brake fluid into brake cylinder 215.

[0040] An exemplary brake 120 includes a plurality of fluid lines 230. The fluid lines 230 allow brake fluid to move to the brake pads 205, thereby slowing the rotation of the wheel. The fluid lines 230 may be, for example, pipes connecting components of the brake 120; for instance, the fluid lines 230 may connect the brake cylinder 215 to a fluid reservoir 240. The fluid lines 230 may be made of flexible materials (e.g., plastic, metal mesh, etc.) and / or the fluid lines 230 may be made of rigid materials (e.g., metal, ceramic, etc.).

[0041] An exemplary brake 120 includes a brake fluid pump 235. The brake fluid pump 235 moves brake fluid through a fluid line 230 to the brake pads 205, thereby slowing the rotation of the wheels 200. A computer 105 can actuate the brake fluid pump 235 to stop the vehicle 101. The brake fluid pump 235 may include a motor (not shown) and a piston (not shown). The computer 105 can actuate the motor to move the piston, thereby pumping brake fluid through the fluid line 230 to the brake pads 205. The computer 105 can actuate the brake fluid pump 235 to obtain a predetermined brake fluid pressure to maintain a predetermined braking torque to brake at least one of the wheels 200. As described below, the predetermined brake fluid pressure can be a brake fluid pressure determined to output a specific braking torque on the wheels 200.

[0042] An exemplary brake 120 includes a fluid reservoir 240. The fluid reservoir 240 stores the brake fluid used in the brake 120. The fluid reservoir 240 is connected to a fluid line 230. Depending on whether the user actuates the brake pedal 210 and / or whether the computer 105 actuates the brake fluid pump 235 to slow the rotation of the wheel 200, the brake 120 may require different volumes of brake fluid. Excess brake fluid can be stored in the fluid reservoir 240 when not needed, while brake fluid can be moved from the fluid reservoir 240 to the brake pads 205, brake cylinder 215, and / or brake fluid pump 235 when needed.

[0043] An exemplary brake 120 includes a plurality of brake fluid valves 245. The brake fluid valves 245 open and close fluid lines 230, thereby allowing brake fluid to move through the fluid lines 230 to specific parts of the brake 120. The brake fluid valves 245 are movable from an open position to a closed position. In the open position, such as... Figures 2 to 3 As indicated by the arrow in brake fluid valve 245, brake fluid valve 245 allows fluid to pass through the fluid line. In the closed position, as... Figures 2 to 3 The parallel lines with gaps between the brake fluid valves 245 in the diagram show that the brake fluid valves 245 prevent brake fluid from flowing through the fluid line 230. The computer 105 can actuate the brake fluid valves 245 to obtain a specified brake fluid pressure, thereby maintaining a specified braking torque (e.g., determined based on Equation 1 below).

[0044] Brake fluid valve 245 may include at least one deflector valve 250. The deflector valve 250 connects a fluid line 230 to connect brake cylinder 215 to fluid reservoir 240. When the deflector valve 250 is in the open position, brake fluid moves from brake cylinder 215 to fluid reservoir 240 without contacting brake pads 205. Computer 105 may determine to open deflector valve 250 to prevent brake fluid from moving from brake cylinder 215 to brake pads 205. Therefore, when computer 105 determines that actuation of brake cylinder 215 should not increase wheel braking, computer 105 may open deflector valve 250 to direct brake fluid from brake cylinder 215 to fluid reservoir 240.

[0045] Brake fluid valve 245 may include at least one isolation valve 255. The isolation valve 255 connects fluid line 230 to connect brake cylinder 215 to brake pad 205. When isolation valve 255 is in the open position, brake fluid can move from brake cylinder 215 to brake pad 205. When isolation valve 255 is in the closed position, brake fluid stops moving from brake cylinder 215 to brake pad 205. Computer 105 may determine to close isolation valve 255 to prevent brake fluid from moving from brake cylinder 215 to brake pad 205 (i.e., isolating brake cylinder 215). Isolation valve 255 may include check valve 260 (i.e., one-way valve) that allows brake fluid to move from brake cylinder 215 to brake pad 205 when brake fluid pressure exceeds a predetermined threshold (e.g., based on the pressure rating of check valve 260). That is, even when isolation valve 255 is in the closed position, brake fluid can still move to brake pad 205 through check valve 260 when brake fluid pressure exceeds the predetermined threshold.

[0046] An exemplary brake 120 includes at least one pressure sensor 110, such as a pressure gauge, piezoresistive strain gauge, variable capacitor, etc. The pressure sensor 110 can determine the brake fluid pressure in the fluid line 230. A computer 105 can actuate the pressure sensor 110 to collect pressure data 115 and determine the brake fluid pressure. Based on the brake fluid pressure indication data 115 from the pressure sensor 110, the computer 105 can actuate the brake fluid valve 245 and the brake fluid pump 235 to adjust the brake fluid pressure to a specified brake fluid pressure.

[0047] Computer 105 can determine the braking torque. Braking torque is the torque applied to the wheels 200 to slow them down, thereby braking the vehicle 101. The braking torque can be determined based on brake fluid pressure data 115.

[0048] τ=2μrpA (1)

[0049] Where τ is the braking torque, μ is the coefficient of friction between the brake pad 205 and the wheel 200, r is the radius of one of the wheels 200, A is the contact area between one of the brake pads 205 and the corresponding wheel 200, and p is the brake fluid pressure. Since μ, r, and A are fixed values ​​for each vehicle 101, the braking torque τ only changes when the brake fluid pressure changes. Therefore, in order to output the specified braking torque τ, the computer 105 can determine the specified brake fluid pressure p through Equation 1 and actuate the brake fluid pump 235 to obtain the specified brake fluid pressure.

[0050] An exemplary brake 120 may include at least one acceleration sensor 110. A computer 105 may actuate the acceleration sensor 110 to determine the acceleration of the vehicle 101. The computer 105 may determine a predetermined acceleration to brake the vehicle 101, and the computer 105 may determine a predetermined braking torque to obtain the predetermined acceleration.

[0051]

[0052] Where a is the specified acceleration and m v The mass of vehicle 101. Computer 105 can determine the prescribed acceleration based on, for example, the distance between vehicle 101 and an object, the current speed of vehicle 101, etc. When computer 105 actuates brake 120, computer 105 can collect acceleration data 115 to determine whether the prescribed braking torque produces the prescribed acceleration to slow down and stop vehicle 101.

[0053] Figure 3 An exemplary brake 120 is shown when a user of vehicle 101 provides input to brake pedal 210. Computer 105 can actuate brake fluid pump 235 to generate a prescribed brake fluid pressure to maintain a prescribed braking torque. When the user applies brake pedal 210, brake fluid from brake cylinder 215 can enter fluid line 230, thereby increasing the brake fluid pressure beyond the prescribed brake fluid pressure, and thus increasing the braking torque.

[0054] Computer 105 can detect user input to brake pedal 210. Computer 105 can actuate pressure sensor 110 to collect pressure data 115. Computer 105 can determine brake fluid pressure based on pressure data 115. When brake fluid pressure exceeds a specified brake fluid pressure, computer 105 can determine that the user has provided input to brake pedal 210.

[0055] Computer 105 can actuate acceleration sensor 110 to collect acceleration data 115. Computer 105 can determine the acceleration of vehicle 101 based on acceleration data 115. When the acceleration exceeds a predetermined acceleration, computer 105 can determine that the user has provided input to brake pedal 210. The predetermined acceleration can be, for example, determined to be the acceleration that slows vehicle 101 down to the speed of an object in front of vehicle 101.

[0056] Computer 105 can actuate brake pedal 210 angle sensor 110 to collect brake pedal 210 angle data 115. Brake pedal 210 angle sensor 110 can be, for example, a potentiometer that outputs a specific voltage based on the rotation of a dial on a potentiometer, a magnetoresistive element that measures the orientation of a magnetic field, a rotary encoder, etc. Computer 105 can determine the brake pedal 210 angle from the brake pedal 210 angle data 115. The brake pedal 210 can, for example, define the angle between a first position and the current position of the brake pedal 210 based on the rotation of a dial on a potentiometer, which is measured by the movement of brake pedal 210 angle sensor 110. When the brake pedal 210 angle exceeds a brake pedal 210 angle threshold (e.g., determined based on the user's experience data 115 of providing input to the brake pedal), computer 105 can determine that the user has provided input to the brake pedal 210.

[0057] Computer 105 can determine the braking torque based on data 115 collected from sensor 110 and at least one of the above equations. When the braking torque exceeds the specified braking torque, computer 105 can determine that the user has provided input to brake pedal 210. Then, computer 105 can determine to reduce the brake fluid pressure to maintain the specified braking torque.

[0058] To relieve brake fluid pressure, computer 105 can actuate tilt valve 250 to allow brake fluid to move into fluid reservoir 240. Computer 105 can actuate tilt valve 250 to the open position, thereby connecting fluid line 230 between brake cylinder 215 and fluid reservoir 240. Computer 105 can actuate tilt valve 250 until brake fluid pressure decreases to maintain a specified braking torque.

[0059] Computer 105 can actuate the tilt valve 250 in a "periodic shutter" mode. In the periodic shutter mode, computer 105 opens and closes the tilt valve 250 multiple times consecutively, thereby causing the brake fluid pressure to decrease more slowly than if the tilt valve 250 were opened and held in the open position. Furthermore, operating the tilt valve 250 in the periodic shutter mode prevents sudden changes in brake fluid pressure by causing a slow decrease in brake fluid pressure, thus preventing sudden changes in the braking torque and acceleration of vehicle 101. For example, computer 105 can actuate the tilt valve at a timed manner similar to that of an anti-lock braking system. In another example, computer 105 can instruct the tilt valve 250 to move between an open and closed position at a predetermined rate (e.g., 15 times per second), where each "movement" includes one opening and one closing of the tilt valve 250.

[0060] Computer 105 can actuate pressure sensor 110 to determine brake fluid pressure and, based on brake fluid pressure data 115, actuate tilt valve 250 in a periodic shutter mode. Computer 105 can compare brake fluid pressure data 115 with a specified brake fluid pressure to maintain a specified braking torque. When brake fluid pressure data 115 indicates that the brake fluid pressure is greater than the specified brake fluid pressure, computer 105 can actuate tilt valve 250 in a periodic shutter mode. When brake fluid pressure data 115 indicates that the brake fluid pressure is lower than the specified brake fluid pressure (or within a predetermined pressure threshold, for example, based on empirical test data of the specified brake fluid pressure), computer 105 can actuate tilt valve 250 to the closed position.

[0061] Computer 105 can actuate tilt valve 250 in a periodic shutter mode for a predetermined period of time to reduce brake fluid pressure. Based on the length of fluid line 230, the amount of brake fluid moving from brake cylinder 215, and the operation of brake fluid pump 235, brake fluid pressure may vary with a hysteresis effect after tilt valve 250 is actuated. That is, after tilt valve 250 is opened, brake fluid pressure may not begin to decrease immediately because brake fluid moves through tilt valve 250 into fluid reservoir 240. Furthermore, after tilt valve 250 is closed, brake fluid pressure may continue to decrease because brake fluid moves from tilt valve 250 into fluid reservoir before stabilizing. Therefore, in order to reduce the brake fluid pressure to a specified brake fluid pressure and maintain that specified brake fluid pressure, the computer 105 can actuate the tilt valve 250 in a periodic shutter mode for a predetermined time period, close the tilt valve 250, wait for a second predetermined time period based on an empirically determined hysteresis length, and then collect brake fluid pressure data 115 from the pressure sensor 110 after the brake fluid pressure no longer continues to decrease. Then, when the brake fluid pressure data 115 indicates that the brake fluid pressure is still higher than the specified brake fluid pressure, the computer 105 can actuate the tilt valve 250.

[0062] Figure 4 An exemplary process 400 for operating vehicle 101 is shown. Process 400 begins at block 405, where computer 105 actuates one or more sensors 110 to collect data 115. Computer 105 may actuate, for example, pressure sensors 110 to determine brake fluid pressure, may actuate ultrasonic and / or radar and / or lidar sensors 110 to detect nearby objects that may require braking, etc.

[0063] Next, in box 410, computer 105 uses, for example, the relationship shown in Equation 1 above to determine a specified braking torque and a specified brake fluid pressure to obtain the specified braking torque. As described above, after determining the actuation of brake 120, computer 105 can determine the specified braking torque to brake vehicle 101. Computer 105 can determine the specified brake fluid pressure to output the specified braking torque.

[0064] Next, in block 415, computer 105 actuates brake fluid pump 235 to output a specified brake fluid pressure. Computer 105 can actuate a motor in brake fluid pump 235 to move a piston, thereby changing the brake fluid pressure in fluid line 230 to generate the specified brake fluid pressure. Computer 105 can collect data 115 from pressure sensor 110 to determine when the brake fluid pressure is within the specified brake fluid pressure threshold.

[0065] Next, in box 420, computer 105 determines whether to release the brake fluid pressure. Computer 105 can collect data 115 from pressure sensor 110 to determine the brake fluid pressure. When the brake fluid pressure exceeds a specified brake fluid pressure, as described above, computer 105 can determine to release the brake fluid pressure. For example, if the user of vehicle 101 depresses brake pedal 210, the brake fluid from the brake cylinder can increase the brake fluid pressure, thereby increasing the braking torque to above a specified braking torque. Computer 105 can release the brake fluid pressure to reduce the braking torque to the specified braking torque. If computer 105 determines to release the brake fluid pressure, process 400 continues in box 425. Otherwise, process 400 can continue in box 430.

[0066] In block 425, computer 105 actuates one or more brake fluid valves 245 to relieve brake fluid pressure. As described above, computer 105 can actuate one or more tilt valves 250 to allow brake fluid to move from brake cylinder 215 to fluid reservoir 240, thereby reducing brake fluid pressure. Computer 105 can actuate tilt valves 250 in a periodic shutter mode, i.e., continuously opening and closing tilt valves 250, so that the brake fluid pressure decreases more slowly than if tilt valves 250 were held in the open position.

[0067] In box 430, computer 105 determines whether to continue process 400. Computer 105 may determine to continue process 400 to determine whether the brake fluid pressure remains above a specified brake fluid pressure. As mentioned above, brake fluid pressure may have a hysteresis effect, and brake fluid pressure may decrease over a period of time longer than the response time of pressure sensor 110. Therefore, computer 105 may continue process 400 until the brake fluid pressure stabilizes at the specified brake fluid pressure. If computer 105 determines to continue, process 400 returns to box 405 to collect more data 115. Otherwise, process 400 terminates.

[0068] As used in this article, the adverb "basically" that modifies an adjective means that the shape, structure, measurement, value, calculation, etc., may deviate from the precise description of the geometry, distance, measurement, value, calculation, etc., because of defects in materials, processing, manufacturing, data acquisition, measurement, calculation, processing time, communication time, etc.

[0069] Computer 105 typically includes instructions, each executable by one or more computing devices (such as those identified above) for carrying out the processes described above. These computer-executable instructions can be compiled or interpreted by computer programs created using various programming languages ​​and / or technologies, including but not limited to Java, either individually or in combination. TMC, C++, Visual Basic, JavaScript, Perl, HTML, etc. Generally, a processor (e.g., a microprocessor) receives instructions from memory, computer-readable media, etc., and executes those instructions, thereby performing one or more processes, including one or more of the processes described herein. Such instructions and other data can be stored and transmitted using various computer-readable media. A file in computer 105 is typically a collection of data stored on computer-readable media (such as storage media, random access memory, etc.).

[0070] Computer-readable media include any medium that contributes to providing data (e.g., instructions) that can be read by a computer. Such media can take many forms, including but not limited to non-volatile media, volatile media, etc. Non-volatile media include, for example, optical discs or magnetic disks and other permanent storage devices. Non-volatile media include dynamic random access memory (DRAM), which typically constitutes main memory. Common forms of computer-readable media include, for example, floppy disks, floppy disks, hard disks, magnetic tape, any other magnetic media, CD-ROMs, DVDs, any other optical media, punched cards, paper tape, any other physical media with a perforated pattern, RAM, PROMs, EPROMs, flash EEPROMs, any other memory chips or storage cartridges, magnetic tape, or any other media from which a computer can read.

[0071] Regarding the media, processes, systems, methods, etc., described herein, it should be understood that although the steps of such processes, etc., are described as occurring in a specific sequence, such processes can be practiced by performing the described steps in an order other than that described herein. It should also be understood that some steps may be performed simultaneously, other steps may be added, or some steps described herein may be omitted. For example, in process 400, one or more steps may be omitted, or they may be performed in a different order than... Figure 4 The steps are executed in the order shown. In other words, the description of the system and / or process herein is provided for the purpose of illustrating certain embodiments and should in no way be construed as limiting the subject matter disclosed.

[0072] Therefore, it should be understood that this disclosure, including the foregoing description and drawings and the following claims, is illustrative and not restrictive. After reading the foregoing description, many embodiments and applications, in addition to the examples provided, will be apparent to those skilled in the art. The scope of the invention should not be determined by reference to the foregoing description, but rather by reference to the claims appended to the invention and included in the non-provisional patent applications based on the invention, and the full scope of their equivalents. Future developments are conceivable and anticipated in the technology discussed herein, and the disclosed systems and methods will be incorporated into such future embodiments. In conclusion, it should be understood that the disclosed subject matter is capable of modifications and variations.

[0073] Unless otherwise specified or required by the context, the article “a” modifying a noun should be understood to refer to one or more. The phrase “based on” implies being partially or completely based on.

[0074] According to the present invention, a system is provided having a computer including a processor and a memory storing instructions executable by the processor for: actuating a vehicle brake according to a predetermined braking torque; receiving user input to exceed the predetermined braking torque; and actuating a brake fluid valve to obtain brake fluid pressure thereby maintaining the predetermined braking torque.

[0075] According to an embodiment, the instructions also include instructions for actuating the brake fluid pump to obtain brake fluid pressure thereby maintaining a specified braking torque.

[0076] According to an embodiment, the instructions also include instructions for recognizing user input based on data of at least one of vehicle acceleration, braking torque, and brake fluid pressure.

[0077] According to an embodiment, the instructions also include instructions for actuating the brake fluid valve to connect the brake cylinder to the fluid reservoir.

[0078] According to an embodiment, the instructions also include instructions for actuating a brake fluid valve to isolate the brake cylinder from the brake.

[0079] According to an embodiment, the instructions also include instructions for actuating a brake fluid valve when the vehicle acceleration exceeds an acceleration threshold.

[0080] According to an embodiment, the instructions also include instructions for actuating the brake valve in a periodic shutter mode to reduce the brake fluid pressure.

[0081] According to an embodiment, the instructions further include instructions for performing the following: opening the brake fluid valve after receiving user input to the brake pedal; closing the brake fluid valve after a predetermined time period; determining the current brake fluid pressure; and opening the brake fluid valve to maintain a predetermined braking torque when the current brake fluid pressure is greater than a specified brake fluid pressure.

[0082] According to an embodiment, the instructions also include instructions for identifying user input to the brake pedal based on data collected from the brake pedal angle sensor.

[0083] According to the present invention, a vehicle braking system is provided, comprising: a brake pedal; a brake fluid pump; a brake fluid valve in communication with the brake pedal; means for actuating the brake fluid pump according to a predetermined braking torque; means for receiving a user input exceeding the predetermined braking torque; and means for actuating the brake fluid valve upon receiving the user input to obtain brake fluid pressure thereby maintaining the predetermined braking torque.

[0084] According to an embodiment, the invention is further characterized by a device for identifying user input based on data of at least one of vehicle acceleration, braking torque, and brake fluid pressure.

[0085] According to an embodiment, the invention is further characterized by means for actuating a brake fluid valve to connect a brake cylinder to a fluid reservoir.

[0086] According to an embodiment, the invention is further characterized by a device for actuating a brake fluid valve to isolate the brake cylinder from the brake fluid pump.

[0087] According to an embodiment, the invention is further characterized by: means for opening the brake fluid valve after receiving user input to the brake pedal; means for closing the brake fluid valve after a predetermined time period; means for determining the current brake fluid pressure; and means for opening the brake fluid valve to output a predetermined braking torque when the current brake fluid pressure is greater than a predetermined brake fluid pressure.

[0088] According to the present invention, a method includes: actuating a vehicle brake according to a predetermined braking torque; receiving user input to exceed the predetermined braking torque; and actuating a brake fluid valve to obtain brake fluid pressure thereby maintaining the predetermined braking torque.

[0089] According to an embodiment, the invention is further characterized in that the brake fluid pump is actuated to obtain brake fluid pressure thereby maintaining a specified braking torque.

[0090] According to an embodiment, the invention is further characterized in that user input is identified based on data of at least one of vehicle acceleration, braking torque, and brake fluid pressure.

[0091] According to an embodiment, the invention is further characterized by actuating a brake fluid valve to connect a brake cylinder to a fluid reservoir.

[0092] According to an embodiment, the invention is further characterized in that the brake fluid valve is actuated to isolate the brake cylinder from the brake.

[0093] According to an embodiment, the invention is further characterized by: opening the brake fluid valve after receiving user input on the brake pedal; closing the brake fluid valve after a predetermined time period; determining the current brake fluid pressure; and opening the brake fluid valve to output a predetermined braking torque when the current brake fluid pressure is greater than a predetermined brake fluid pressure.

Claims

1. A method for vehicle braking operation, comprising: Determine the specified braking torque to obtain the specified acceleration; Actuate the vehicle brakes according to the specified braking torque; Receive user input for a braking torque exceeding the specified value; as well as The brake fluid valve is actuated to obtain brake fluid pressure, thereby maintaining the specified braking torque.

2. The method of claim 1, further comprising actuating a brake fluid pump to obtain the brake fluid pressure thereby maintaining the prescribed brake torque.

3. The method of claim 1, further comprising identifying the user input based on data of at least one of vehicle acceleration, the braking torque, and the braking fluid pressure.

4. The method of claim 1, further comprising actuating the brake fluid valve to connect the brake cylinder to a fluid reservoir.

5. The method of claim 1, further comprising actuating the brake fluid valve to isolate the brake cylinder from the brake.

6. The method of claim 1, further comprising actuating the brake fluid valve when the vehicle acceleration exceeds an acceleration threshold.

7. The method of claim 1, further comprising actuating the brake fluid valve in a periodic shutter mode to reduce the brake fluid pressure.

8. The method of claim 1, further comprising: The brake fluid valve opens upon receiving user input for the brake pedal. Close the brake fluid valve after a predetermined time period; Determine the current brake fluid pressure; And when the current brake fluid pressure is greater than the specified brake fluid pressure, the brake fluid valve is opened to maintain the specified brake torque.

9. The method of claim 1, further comprising identifying the user input to the brake pedal based on data collected from the brake pedal angle sensor.

10. The method of any one of claims 3-9, further comprising actuating a brake fluid pump to obtain the brake fluid pressure thereby maintaining the prescribed brake torque.

11. The method of any one of claims 2-6 and 8-9, further comprising actuating the brake fluid valve in a periodic shutter mode to reduce the brake fluid pressure.

12. The method according to any one of claims 2-7 and 9, further comprising: The brake fluid valve is opened upon receiving user input for the brake pedal. Close the brake fluid valve after a predetermined time period; Determine the current brake fluid pressure; And when the current brake fluid pressure is greater than the specified brake fluid pressure, the brake fluid valve is opened to maintain the specified brake torque.

13. A computer programmed to perform the method of any one of claims 1-9.

14. A vehicle comprising the computer as described in claim 13.

15. A computer program product comprising a computer-readable medium storing instructions executable by a computer processor to perform the method of any one of claims 1-9.

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