A PV characteristic calibration method, device, system and vehicle for a braking system

Abstract

The present invention discloses a PV characteristic calibration method, device, system and vehicle for a brake system, the method comprising: confirming the entry into the PV characteristic calibration process; dividing the entire PV characteristic calibration process into multiple calibration stages based on the opening range of the brake pedal; executing the calibration stage to obtain a PV characteristic data group; performing polynomial fitting on all PV characteristic data groups to obtain a fitting function; confirming that the fitting degree of the fitting function meets the set requirements; obtaining sample points of the current PV characteristic parameters, substituting the sample points into the fitting function, and calculating the mean square error value, when the mean square error value is greater than 0.05, all PV characteristic data groups are used as the current PV characteristic parameters. The present invention can enable non-professionals to easily complete the PV characteristic calibration. The present invention is mainly used in the field of automotive technology.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a PV characteristic calibration method, device, system and vehicle for a braking system. Background Art

[0002] The PV (pressure-displacement) characteristic of the brake is a very important characteristic parameter in the development of the vehicle braking system. The PV characteristic represents the relationship between the brake pressure that the brake can generate and the pedal displacement input by the driver. It depends on many factors such as the caliper piston cylinder diameter and number of the brake system, the disc gap, the friction plate stiffness, the oil pipe volume, etc. In the development process of electronic control braking systems such as ESC and integrated brake control assembly, it is necessary to test the hardware parameters of the vehicle's braking system first to confirm the PV characteristics of the system and then provide support for the pressure building characteristics of the ESC system (ESC stands for Electronic-Stability-Controller, which is an active safety technology that assists the driver in controlling the vehicle). This is especially true for electronic control braking systems such as one box, where the pedal is decoupled from the hydraulic system. The PV characteristics of the brake system will also affect the pedal feel, and are also the basis for determining whether there is a leak in the brake system, which is closely related to the safety of the entire vehicle.

[0003] When the brake selection is confirmed, the PV characteristics of the brake system are also confirmed. The calibration engineer will confirm a suitable PV fluctuation range based on the characteristics of the caliper and other components to eliminate the impact of manufacturing errors and other factors on the PV characteristics, so as to increase the robustness of the system. However, for many car owners who pursue performance, they are often not satisfied with the pre-settings of the OEM. In the modification market, the calipers, friction plates and other parts of the vehicle will be upgraded. (Such as enlarging the piston, increasing the number of pistons, etc.) For these requirements, the parameters pre-set by the OEM often do not cover these requirements. After replacing the brake system, if the electronic control system still applies the previous calibration parameters, it will have a significant impact on the response characteristics of the brake system of the whole vehicle and even cause failures, affecting safety. How to allow non-professionals such as drivers to perform PV characteristic calibration is a topic that urgently needs to be studied in the industry. Summary of the invention

[0004] The present invention provides a PV characteristic calibration method, device, system and vehicle for a brake system to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions.

[0005] The present invention provides a PV characteristic calibration method for a braking system, comprising: confirming that a PV characteristic calibration process is entered; dividing the entire PV characteristic calibration process into a plurality of calibration stages based on an opening range of a brake pedal; executing the calibration stage, during which a human-computer interaction interface is controlled to provide prompts so that a calibration personnel can effectively step on the brake pedal for multiple times, wherein the effective stepping is a stepping that makes the opening of the brake pedal conform to the opening range corresponding to the calibration stage; recording the PV characteristic data corresponding to each effective stepping, and recording the set of PV characteristic data obtained in the calibration stage as a PV characteristic data group; performing polynomial fitting on all PV characteristic data groups obtained in the entire PV characteristic calibration process to obtain a fitting function; confirming that the fitting degree of the fitting function meets the set requirements; obtaining sample points of current PV characteristic parameters, substituting the sample points into the fitting function, and calculating a mean square error value, and when the mean square error value is greater than 0.05, all PV characteristic data groups are used as current PV characteristic parameters.

[0006] Furthermore, confirming entry into the PV characteristic calibration process specifically includes: obtaining a request signal input by the calibrator through operation to request entry into the PV characteristic calibration process, evaluating the vehicle state according to the request signal, and when the vehicle state satisfies: the vehicle speed is 0, the gear is in P gear, the brake pedal is not stepped on, and the vehicle is not in a fault degradation mode; then confirming entry into the PV characteristic calibration process.

[0007] Furthermore, taking all the PV characteristic data sets as the current PV characteristic parameters specifically includes: determining a storage address of the current PV characteristic parameters, and overwriting all the PV characteristic data sets as the current PV characteristic parameters into the storage address.

[0008] Furthermore, all PV characteristic data sets obtained in the entire PV characteristic calibration process are subjected to polynomial fitting by a quadratic polynomial method.

[0009] Further, confirming that the fitting degree of the fitting function meets the set requirements specifically includes: calculating the fitting degree R of the fitting function 2 value, when the R 2 If the value is greater than 0.8, it is considered that the fitting degree of the fitting function meets the set requirements.

[0010] Furthermore, when the vehicle status does not satisfy: the vehicle speed is 0, the gear is in P gear, the brake pedal is not stepped on, and the vehicle is not in fault degradation mode, the human-computer interaction interface is controlled to output a prompt message.

[0011] Furthermore, during the calibration phase, the calibration personnel is required to effectively step on the brake pedal more than 20 times.

[0012] On the other hand, a PV characteristic calibration device for a braking system is provided, comprising: a processor and a memory; the memory is used to store a computer-readable program; when the computer-readable program is executed by the processor, the processor implements a PV characteristic calibration method for a braking system as described in any one of the above technical solutions.

[0013] On the other hand, a PV characteristic calibration system for a brake system is provided, comprising: a first confirmation module, a segmentation module, a calibration module, a fitting module, a second confirmation module and a recording module;

[0014] The first confirmation module is used to: confirm the entry into the PV feature calibration process;

[0015] The segmentation module is used to: segment the entire PV characteristic calibration process into multiple calibration stages based on the opening range of the brake pedal;

[0016] The calibration module is used to: execute the calibration phase, during which the human-computer interaction interface is controlled to give prompts so that the calibration personnel can effectively step on the brake pedal for multiple times, wherein the effective stepping is the stepping that makes the opening of the brake pedal conform to the opening range corresponding to the calibration phase; record the PV characteristic data corresponding to each effective stepping, and record the set of PV characteristic data obtained in the calibration phase as a PV characteristic data group;

[0017] The fitting module is used to: perform polynomial fitting on all PV characteristic data sets obtained during the entire PV characteristic calibration process to obtain a fitting function;

[0018] The second confirmation module is used to: confirm that the fitting degree of the fitting function meets the set requirements;

[0019] The recording module is used to obtain sample points of the current PV characteristic parameters, substitute the sample points into the fitting function, and calculate the mean square error value. When the mean square error value is greater than 0.05, all PV characteristic data groups are used as the current PV characteristic parameters.

[0020] On the other hand, a vehicle is provided, which is integrated with the PV characteristic calibration system of the braking system described in the above technical solution.

[0021] The present invention has at least the following beneficial effects: The method of the present invention divides the entire PV characteristic calibration process into stages, and in each stage, a human-computer interaction interface is used for prompting, so that the calibrator can easily complete the calibration of the PV characteristics of the brake system by stepping on the brake pedal. Finally, the reliability of the obtained PV characteristic data is verified, and the PV characteristic data that has passed the reliability verification is used as the current PV characteristic parameter. Thereby, non-professionals can also easily complete the PV characteristic calibration. At the same time, corresponding devices, systems and vehicles are also provided. The beneficial effects of the devices, systems and vehicles are similar to those of the method, and will not be repeated here. The present invention is mainly used in the field of vehicle technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0023] Figure 1 It is a flow chart of the steps of the PV characteristic calibration method of the braking system;

[0024] Figure 2 It is a schematic diagram of the structure of the PV characteristic calibration device of the braking system;

[0025] Figure 3 It is a schematic diagram of the system structure of the PV characteristic calibration system of the braking system. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] It should be noted that, although the functional modules are divided in the system schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the system or the order in the flowchart. The terms "first", "second", etc. in the specification, claims and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0028] Please refer to Figure 1 , Figure 1 The PV characteristic calibration method of the braking system is a flowchart of the steps. The PV characteristic calibration method of the braking system can be executed by the vehicle-mounted intelligent system to implement the steps including:

[0029] Step 1: Confirm to enter the PV characteristic calibration process.

[0030] In this step, when the calibrator (non-professionals such as drivers) wants to perform PV feature calibration, they can operate through the human-computer interaction interface of the vehicle to inform the on-board intelligent system. The on-board intelligent system can confirm through the human-computer interaction interface that the calibrator expects to perform PV feature calibration. Of course, in order to ensure the reliability of the data during the calibration process. Therefore, in some further specific embodiments, after obtaining the request signal input by the calibrator through the operation to request to enter the PV feature calibration process, the on-board intelligent system also needs to evaluate the vehicle status. Only when the vehicle status meets the set conditions can it be allowed to enter the PV feature calibration process. Among them, the vehicle status needs to meet the following conditions at the same time: the vehicle speed is 0, the gear is in P gear, the brake pedal is not stepped on, and the vehicle is not in fault degradation mode.

[0031] Step 2: Based on the opening range of the brake pedal, the entire PV characteristic calibration process is divided into a first calibration stage, a second calibration stage and a third calibration stage.

[0032] After the vehicle-mounted intelligent system confirms that it has entered the PV feature calibration process, it can start the PV feature calibration. Of course, the entire PV feature calibration process needs to be segmented into stages based on the opening range of the brake pedal. This segmentation can make the entire PV feature calibration process more complete for data collection. Of course, for the segmentation of the stages, the more detailed the stage segmentation, the more detailed the collected data will be. Of course, this will also increase the time and cost of the entire calibration process. This specific embodiment divides the entire PV feature calibration process into three calibration stages. They are: the first calibration stage, the second calibration stage, and the third calibration stage. Among them, the opening range of the brake pedal allocated in the first calibration stage is greater than or equal to 0% to less than 30%. The opening range of the brake pedal allocated in the second calibration stage is greater than or equal to 30% to less than 60%. The opening range of the brake pedal allocated in the third calibration stage is greater than or equal to 60% to less than or equal to 100%.

[0033] Step 3: execute the first calibration phase, execute the second calibration phase, and execute the third calibration phase.

[0034] The execution of the first calibration stage, the second calibration stage, and the third calibration stage can be performed in sequence. For example, the first calibration stage is performed first, then the second calibration stage is performed, and finally the third calibration stage is performed. Of course, it can also be performed out of order, such as first performing the second calibration stage, then performing the first calibration stage, and finally performing the first calibration stage. For ease of description, this specific embodiment takes the first calibration stage as an example, then performing the second calibration stage, and finally performing the third calibration stage.

[0035] Among them, for the first calibration stage, the opening range of the brake pedal it is responsible for is greater than or equal to 0% to less than 30%. Therefore, during the execution of the first calibration stage, the on-board intelligent system will output prompt information by controlling the human-computer interaction interface, and the calibration personnel can operate according to the prompt information output by the human-computer interaction interface. The on-board intelligent system will collect PV characteristic data throughout the first calibration stage. Under the prompt of the prompt information output by the human-computer interaction interface, the calibration personnel will lightly step on the brake pedal multiple times. The light step refers to a qualified stepping-relaxing process. The on-board intelligent system will obtain the pressure data generated by the brake and the displacement data of the brake pedal each time the step is stepped on according to the light stepping feedback from the brake system. One light step will generate a PV characteristic data. Of course, in order to ensure that enough PV characteristic data is collected, the number of light steps generally needs to be greater than or equal to 20 times. This specific embodiment is 20 times. Moreover, for the opening of the brake pedal caused by the light step in the first calibration stage, it is necessary to confirm that it is between 0% and 30%. For the sake of convenience, in the first calibration phase, the set of all PV characteristic data collected is recorded as a first PV characteristic data set. The obtained first PV characteristic data set will be stored in a cache for future use.

[0036] For the second calibration stage, the opening range of the brake pedal it is responsible for is greater than or equal to 30% to less than 60%. Therefore, during the execution of the second calibration stage, the on-board intelligent system will output prompt information by controlling the human-computer interaction interface, and the calibration personnel can operate according to the prompt information output by the human-computer interaction interface. The on-board intelligent system will collect PV characteristic data throughout the second calibration stage. Under the prompt of the prompt information output by the human-computer interaction interface, the calibration personnel will lightly step on the brake pedal multiple times. The light step refers to a qualified stepping-relaxing process. The on-board intelligent system will obtain the pressure data generated by the brake and the displacement data of the brake pedal each time the step is stepped on according to the light stepping feedback from the brake system. One light step will generate a PV characteristic data. Of course, in order to ensure that enough PV characteristic data is collected, the number of light steps generally needs to be greater than or equal to 20 times. This specific embodiment is 20 times. Moreover, for the opening of the brake pedal caused by the light step in the second calibration stage, it is necessary to confirm that it is between 30% and 60%. For the sake of convenience, in the second calibration phase, the set of all PV characteristic data collected is recorded as a second PV characteristic data set. The obtained second PV characteristic data set will be stored in a cache for future use.

[0037] For the third calibration stage, the opening range of the brake pedal it is responsible for is greater than or equal to 60% to less than or equal to 100%. Therefore, during the execution of the third calibration stage, the vehicle-mounted intelligent system will output prompt information by controlling the human-computer interaction interface, and the calibration personnel can operate according to the prompt information output by the human-computer interaction interface. The vehicle-mounted intelligent system will collect PV characteristic data throughout the third calibration stage. Under the prompt of the prompt information output by the human-computer interaction interface, the calibration personnel will lightly step on the brake pedal multiple times. The light step refers to a qualified stepping-relaxing process. The vehicle-mounted intelligent system will obtain the pressure data generated by the brake and the displacement data of the brake pedal each time the step is stepped on according to the light stepping feedback from the braking system. One light step will generate a PV characteristic data. Of course, in order to ensure that enough PV characteristic data is collected, the number of light steps generally needs to be greater than or equal to 20 times. This specific embodiment is 20 times. Moreover, for the opening of the brake pedal caused by the light stepping in the third calibration stage, it is necessary to confirm that it is between 60% and 100%. For the sake of convenience, in the third calibration phase, the collection of all PV characteristic data collected is recorded as a third PV characteristic data set. The obtained third PV characteristic data set will be stored in a cache for future use.

[0038] It should be noted that in the first calibration stage, the second calibration stage and the third calibration stage, if an abnormality occurs during the calibration process, the current calibration stage will be exited. The calibration personnel need to use the human-computer interaction interface to re-enter the corresponding calibration stage.

[0039] After the vehicle-mounted intelligent system obtains the first PV characteristic data set, the second PV characteristic data set and the third PV characteristic data set, it can be considered that it has completed the PV characteristic calibration process.

[0040] The on-board intelligent system needs to process all characteristic data sets obtained during the PV characteristic calibration process.

[0041] Step 4: Perform polynomial fitting on the first PV characteristic data set, the second PV characteristic data set and the third PV characteristic data set to obtain a fitting function.

[0042] Of course, after obtaining the first PV characteristic data set, the second PV characteristic data set and the third PV characteristic data set, it is also necessary to verify whether the collected PV characteristic data is reasonable and conforms to the linear relationship during the entire PV characteristic calibration process. Therefore, the vehicle-mounted intelligent system needs to perform polynomial fitting on the first PV characteristic data set, the second PV characteristic data set and the third PV characteristic data set to obtain a fitting function. Then, by judging the fitting function, it is determined whether the obtained PV calibration data is reasonable.

[0043] Step 5: confirm that the fitting degree of the fitting function meets the set requirements.

[0044] The vehicle-mounted intelligent system pre-stores the requirements for the degree of fit of the fitting function, and the vehicle-mounted intelligent system can call and judge to determine whether the degree of fit of the fitting function meets the set requirements. In some further specific embodiments, the vehicle-mounted intelligent system calculates the degree of fit R of the fitting function. 2 value, when the R 2 If the value is greater than 0.8, it is considered that the fitting degree of the fitting function meets the set requirements.

[0045] Step 6: Obtain sample points of the current PV characteristic parameters, substitute the sample points into the fitting function, and calculate the mean square error value. When the mean square error value is greater than 0.05, the first PV characteristic data group, the second PV characteristic data group, and the third PV characteristic data group are used as the current PV characteristic parameters.

[0046] After the on-board intelligent system obtains the fitting function and confirms that the fitting degree of the fitting function meets the requirements, it is also necessary to determine that the fitting function meets the allowable error range of the PV fluctuation of the vehicle's braking system. To this end, the on-board intelligent system also needs to obtain the sample points of the current PV characteristic parameters. The sample points of the current PV characteristic parameters refer to the original PV characteristic data for the current braking system that already exists before the PV characteristic calibration. The reliability of the fitting function can be tested through the original PV characteristic data. Of course, the number and distribution of the sample points of the PV characteristic parameters are selected according to pre-set rules, in order to make a comprehensive judgment on the fitting function.

[0047] The vehicle-mounted intelligent system substitutes the sample points of the obtained PV characteristic parameters into the fitting function and calculates the mean square error. When the mean square error value is greater than 0.05, it can be considered that the fitting function is in line with the error range allowed by PV fluctuations. Therefore, at this time, the first PV characteristic data group, the second PV characteristic data group and the third PV characteristic data group can be used as the current PV characteristic parameters to replace the original PV characteristic data.

[0048] The present invention divides the entire PV characteristic calibration process into stages, and in each stage, a human-computer interaction interface is used for prompting, so that the calibration personnel can easily complete the PV characteristic calibration of the brake system by stepping on the brake pedal. Finally, the reliability of the obtained PV characteristic data is verified, and the PV characteristic data that has passed the reliability verification is used as the current PV characteristic parameter. Therefore, non-professionals can also easily complete the PV characteristic calibration.

[0049] In some further specific embodiments, the vehicle-mounted intelligent system uses all PV characteristic data groups obtained in the entire PV characteristic calibration process as the current PV characteristic parameters, specifically including: the vehicle-mounted intelligent system first needs to determine the storage address of the current PV characteristic parameters, and writes all the obtained PV characteristic data groups as the current PV characteristic parameters to the storage address. In this specific embodiment, the first PV characteristic data group, the second PV characteristic data group, and the third PV characteristic data group can be written as the current PV characteristic parameters to the storage address.

[0050] In order to make the entire calibration setting more reasonable, an exit process needs to be set. In some further specific embodiments, when the vehicle intelligent system determines that the vehicle state does not meet the following conditions: the vehicle speed is 0, the gear is in P gear, the brake pedal is not stepped on, and the vehicle is not in a fault degradation mode, the human-computer interaction interface is controlled to output a prompt message. The prompt message is output to inform the calibration personnel that the PV feature calibration process needs to be exited.

[0051] On the other hand, reference Figure 2 , Figure 2 It is a structural schematic diagram of the PV characteristic calibration device of the braking system.

[0052] This specific embodiment also provides a PV characteristic calibration device for a brake system, comprising: a processor and a memory. The memory is used to store a computer-readable program. When the computer-readable program is executed by the processor, the processor implements the PV characteristic calibration method for the brake system as described in any one of the above specific embodiments.

[0053] It will be appreciated by those skilled in the art that all or some of the steps and systems in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or transient medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. As is well known to those skilled in the art, communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0054] On the other hand, reference Figure 3 , Figure 3 It is a schematic diagram of the system structure of the PV characteristic calibration system of the braking system.

[0055] A PV characteristic calibration system for a braking system is provided, comprising: a first confirmation module, a segmentation module, a calibration module, a fitting module, a second confirmation module and a recording module.

[0056] The first confirmation module is used to confirm the entry into the PV characteristic calibration process.

[0057] When the calibration personnel (non-professionals such as drivers) want to perform PV characteristic calibration, they can operate through the human-computer interaction interface of the vehicle to inform the first confirmation module. The first confirmation module confirms through the human-computer interaction interface that the calibrator wishes to perform PV characteristic calibration. Of course, in order to ensure the reliability of the data during the calibration process. Therefore, in some further specific embodiments, after obtaining the request signal input by the calibrator through the operation to request to enter the PV characteristic calibration process, the first confirmation module also needs to evaluate the vehicle status. Only when the vehicle status meets the set conditions can it be allowed to enter the PV characteristic calibration process. Among them, the vehicle status needs to meet the following conditions at the same time: the vehicle speed is 0, the gear is P gear, the brake pedal is not stepped on, and the vehicle is not in fault degradation mode.

[0058] The segmentation module is used to segment the entire PV characteristic calibration process into a first calibration stage, a second calibration stage and a third calibration stage based on the opening range of the brake pedal.

[0059] After the segmentation module confirms that it has entered the PV feature calibration process, the PV feature calibration can be started. Of course, the entire PV feature calibration process needs to be segmented into stages based on the opening range of the brake pedal. This segmentation can make the entire PV feature calibration process more complete for data collection. Of course, for the segmentation of stages, the more detailed the stage segmentation, the more detailed the collected data will be. Of course, this will also increase the time and cost of the entire calibration process. This specific embodiment divides the entire PV feature calibration process into three calibration stages. They are: the first calibration stage, the second calibration stage, and the third calibration stage. Among them, the opening range of the brake pedal allocated in the first calibration stage is greater than or equal to 0% to less than 30%. The opening range of the brake pedal allocated in the second calibration stage is greater than or equal to 30% to less than 60%. The opening range of the brake pedal allocated in the third calibration stage is greater than or equal to 60% to less than or equal to 100%.

[0060] The calibration module is used to: execute a first calibration phase, execute a second calibration phase, and execute a third calibration phase.

[0061] The execution of the first calibration stage, the second calibration stage, and the third calibration stage can be performed in sequence. For example, the first calibration stage is performed first, then the second calibration stage is performed, and finally the third calibration stage is performed. Of course, it can also be performed out of order, such as first performing the second calibration stage, then performing the first calibration stage, and finally performing the first calibration stage. For ease of description, this specific embodiment takes the first calibration stage as an example, then performing the second calibration stage, and finally performing the third calibration stage.

[0062] Among them, for the first calibration stage, the opening range of the brake pedal it is responsible for is greater than or equal to 0% to less than 30%. Therefore, during the execution of the first calibration stage, the calibration module will output prompt information by controlling the human-computer interaction interface, and the calibration personnel can operate according to the prompt information output by the human-computer interaction interface. The calibration module will collect PV characteristic data throughout the first calibration stage. Under the prompt of the prompt information output by the human-computer interaction interface, the calibration personnel will lightly step on the brake pedal multiple times. The light step refers to a qualified stepping-relaxing process. The calibration module will obtain the pressure data generated by the brake and the displacement data of the brake pedal each time the step is stepped on according to the feedback from the braking system. One light step will generate a PV characteristic data. Of course, in order to ensure that enough PV characteristic data is collected, the number of light steps generally needs to be greater than or equal to 20 times. This specific embodiment is 20 times. Moreover, for the opening of the brake pedal caused by the light step in the first calibration stage, it is necessary to confirm that it is between 0% and 30%. For the sake of convenience, in the first calibration phase, the set of all PV characteristic data collected is recorded as a first PV characteristic data set. The obtained first PV characteristic data set will be stored in a cache for future use.

[0063] For the second calibration stage, the opening range of the brake pedal it is responsible for is greater than or equal to 30% to less than 60%. Therefore, during the execution of the second calibration stage, the calibration module will output prompt information by controlling the human-computer interaction interface, and the calibration personnel can operate according to the prompt information output by the human-computer interaction interface. The calibration module will collect PV characteristic data throughout the second calibration stage. Under the prompt of the prompt information output by the human-computer interaction interface, the calibration personnel will lightly step on the brake pedal multiple times. The light step refers to a qualified stepping-relaxing process. The calibration module will obtain the pressure data generated by the brake and the displacement data of the brake pedal each time the step is stepped on according to the feedback from the braking system. One light step will generate a PV characteristic data. Of course, in order to ensure that enough PV characteristic data is collected, the number of light steps generally needs to be greater than or equal to 20 times. This specific embodiment is 20 times. Moreover, for the opening of the brake pedal caused by the light step in the second calibration stage, it is necessary to confirm that it is between 30% and 60%. For the sake of convenience, in the second calibration phase, the set of all PV characteristic data collected is recorded as a second PV characteristic data set. The obtained second PV characteristic data set will be stored in a cache for future use.

[0064] For the third calibration stage, the opening range of the brake pedal it is responsible for is greater than or equal to 60% to less than or equal to 100%. Therefore, during the execution of the third calibration stage, the calibration module will output prompt information by controlling the human-computer interaction interface, and the calibration personnel can operate according to the prompt information output by the human-computer interaction interface. The calibration module will collect PV characteristic data throughout the third calibration stage. Under the prompt of the prompt information output by the human-computer interaction interface, the calibration personnel will lightly step on the brake pedal multiple times. The light step refers to a qualified stepping-relaxing process. The calibration module will obtain the pressure data generated by the brake and the displacement data of the brake pedal each time the step is stepped on according to the feedback from the braking system. One light step will generate a PV characteristic data. Of course, in order to ensure that enough PV characteristic data is collected, the number of light steps generally needs to be greater than or equal to 20 times. This specific embodiment is 20 times. Moreover, for the opening of the brake pedal caused by the light step in the third calibration stage, it is necessary to confirm that it is between 60% and 100%. For the sake of convenience, in the third calibration phase, the collection of all PV characteristic data collected is recorded as a third PV characteristic data set. The obtained third PV characteristic data set will be stored in a cache for future use.

[0065] It should be noted that in the first calibration stage, the second calibration stage and the third calibration stage, if an abnormality occurs during the calibration process, the current calibration stage will be exited. The calibration personnel need to use the human-computer interaction interface to re-enter the corresponding calibration stage.

[0066] After the calibration module obtains the first PV characteristic data set, the second PV characteristic data set and the third PV characteristic data set, it can be considered that the PV characteristic calibration process has been completed.

[0067] The fitting module is used to perform polynomial fitting on the first PV characteristic data set, the second PV characteristic data set and the third PV characteristic data set to obtain a fitting function.

[0068] Of course, after obtaining the first PV characteristic data set, the second PV characteristic data set and the third PV characteristic data set, it is also necessary to verify whether the collected PV characteristic data is reasonable and conforms to the linear relationship during the entire PV characteristic calibration process. Therefore, the fitting module needs to perform polynomial fitting on the first PV characteristic data set, the second PV characteristic data set and the third PV characteristic data set to obtain a fitting function. Then, by judging the fitting function, it is determined whether the obtained PV calibration data is reasonable.

[0069] The second confirmation module is used to: confirm that the fitting degree of the fitting function meets the set requirements;

[0070] The second confirmation module pre-stores the requirements for the degree of fit of the fitting function, and the second confirmation module can determine whether the degree of fit of the fitting function meets the set requirements by calling and judging. In some further specific embodiments, the second confirmation module calculates the degree of fit R of the fitting function. 2 value, when the R 2 If the value is greater than 0.8, it is considered that the fitting degree of the fitting function meets the set requirements.

[0071] The recording module is used to obtain sample points of the current PV characteristic parameters, substitute the sample points into the fitting function, and calculate the mean square error value. When the mean square error value is greater than 0.05, all PV characteristic data groups are used as the current PV characteristic parameters.

[0072] After the recording module obtains the fitting function and confirms that the fitting degree of the fitting function meets the requirements, it is also necessary to determine whether the fitting function meets the allowable error range of the PV fluctuation of the vehicle's braking system. To this end, the recording module needs to obtain the sample points of the current PV characteristic parameters. The sample points of the current PV characteristic parameters refer to the original PV characteristic data for the current braking system that already exists before the PV characteristic calibration. The reliability of the fitting function can be tested through the original PV characteristic data. Of course, the number and distribution of the sample points of the PV characteristic parameters are selected according to pre-set rules, in order to make a comprehensive judgment on the fitting function.

[0073] The present invention also provides a vehicle, wherein the PV characteristic calibration system of the braking system described in any one of the above specific embodiments is integrated inside the vehicle.

[0074] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0075] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0076] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0077] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0078] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0079] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), disk or optical disk and other media that can store program codes.

[0080] Although the description of the present application has been quite detailed and specifically describes several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be regarded as providing a broad possible interpretation of these claims by reference to the attached claims, taking into account the prior art, so as to effectively cover the intended scope of the present application. In addition, the above description of the present application is based on the embodiments foreseeable by the inventor, and its purpose is to provide a useful description, and those non-substantial changes to the present application that have not yet been foreseen may still represent equivalent changes to the present application.

Claims

1. A PV characteristic calibration method for a braking system, characterized in that: include: Confirm to enter the PV characteristic calibration process; The entire PV characteristic calibration process is divided into multiple calibration stages based on the opening range of the brake pedal; During the calibration phase, the human-machine interface is controlled to prompt the calibration personnel to effectively step on the brake pedal for multiple times, wherein the effective stepping is the stepping that makes the opening of the brake pedal conform to the opening range corresponding to the calibration phase; Record the PV characteristic data corresponding to each effective pedaling, and record the set of PV characteristic data obtained in the calibration phase as a PV characteristic data group; Perform polynomial fitting on all PV characteristic data sets obtained during the entire PV characteristic calibration process to obtain a fitting function; confirm that the fitting degree of the fitting function meets the set requirements; Obtain sample points of the current PV characteristic parameters, substitute the sample points into the fitting function, and calculate the mean square error value. When the mean square error value is greater than 0.05, all PV characteristic data groups are used as the current PV characteristic parameters; The sample point of the current PV characteristic parameter refers to the original PV characteristic data for the current braking system that already exists before the PV characteristic calibration is performed; Confirming entry into the PV characteristic calibration process specifically includes: obtaining a request signal input by the calibrator through operation to request entry into the PV characteristic calibration process, evaluating the vehicle state according to the request signal, and when the vehicle state satisfies: the vehicle speed is 0, the gear is in P gear, the brake pedal is not stepped on, and the vehicle is not in a fault degradation mode; then confirming entry into the PV characteristic calibration process.

2. A PV characteristic calibration method for a brake system according to claim 1, characterized in that: Taking all PV characteristic data sets as current PV characteristic parameters specifically includes: determining a storage address of the current PV characteristic parameters, and overwriting all PV characteristic data sets as the current PV characteristic parameters into the storage address.

3. The PV characteristic calibration method of a brake system according to claim 1, characterized in that: All PV characteristic data sets obtained during the entire PV characteristic calibration process are polynomially fitted using the quadratic polynomial method.

4. The PV characteristic calibration method of a brake system according to claim 3, characterized in that: Confirming that the fitting degree of the fitting function meets the set requirements specifically includes: calculating the fitting degree R of the fitting function 2 value, when the R 2 If the value is greater than 0.8, it is considered that the fitting degree of the fitting function meets the set requirements.

5. The PV characteristic calibration method of a brake system according to claim 1, characterized in that: When the vehicle status does not meet the following conditions: the vehicle speed is 0, the gear is in P gear, the brake pedal is not stepped on, and the vehicle is not in fault degradation mode, the human-computer interaction interface is controlled to output a prompt message.

6. The PV characteristic calibration method of a brake system according to claim 1, characterized in that: During the calibration phase, the calibrator is required to effectively step on the brake pedal more than 20 times.

7. A PV characteristic calibration device for a braking system, characterized in that: include: processor; A memory for storing a computer readable program; When the computer-readable program is executed by the processor, the processor implements the PV characteristic calibration method of the braking system according to any one of claims 1 to 6.

8. A PV characteristic calibration system for a braking system, characterized in that: include: A first confirmation module, a segmentation module, a calibration module, a fitting module, a second confirmation module and a recording module; The first confirmation module is used to: confirm the entry into the PV feature calibration process; The segmentation module is used to: segment the entire PV characteristic calibration process into multiple calibration stages based on the opening range of the brake pedal; The calibration module is used to: execute the calibration phase, during which the human-computer interaction interface is controlled to prompt the calibration personnel to effectively step on the brake pedal multiple times, wherein the effective stepping is the stepping that makes the opening of the brake pedal conform to the opening range corresponding to the calibration phase; Record the PV characteristic data corresponding to each effective pedaling, and record the set of PV characteristic data obtained in the calibration phase as a PV characteristic data group; The fitting module is used to: perform polynomial fitting on all PV characteristic data sets obtained during the entire PV characteristic calibration process to obtain a fitting function; The second confirmation module is used to: confirm that the fitting degree of the fitting function meets the set requirements; The recording module is used to: obtain sample points of the current PV characteristic parameters, substitute the sample points into the fitting function, and calculate the mean square error value. When the mean square error value is greater than 0.05, all PV characteristic data groups are used as the current PV characteristic parameters; The sample point of the current PV characteristic parameter refers to the original PV characteristic data for the current braking system that already exists before the PV characteristic calibration is performed; Confirming entry into the PV characteristic calibration process specifically includes: obtaining a request signal input by the calibrator through operation to request entry into the PV characteristic calibration process, evaluating the vehicle state according to the request signal, and when the vehicle state satisfies: the vehicle speed is 0, the gear is in P gear, the brake pedal is not stepped on, and the vehicle is not in a fault degradation mode; then confirming entry into the PV characteristic calibration process.

9. A vehicle, characterized in that: A PV characteristic calibration system incorporating the braking system of claim 8.

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