A method and device for monitoring the consistency of braking force response of an unmanned vehicle

Abstract

The present invention provides a method and device for monitoring the consistency of the braking force response of an unmanned vehicle. By obtaining the braking response characteristics of the service brake system, the target response time corresponding to each target braking deceleration is calculated in real time. The target response time is used to determine the influence of the target braking force at each previous moment on the actual braking force at each subsequent moment, so as to determine the deviation between the actual theoretical braking force and the actual braking force. By obtaining the maximum value and cumulative average value of the deviation, the interference or error caused by excessive single braking force deviation is avoided, which can greatly improve the accuracy and real-time performance of the braking force response monitoring of the service brake system, and improve the safety of the vehicle under unmanned driving conditions.

Description

Technical Field

[0001] The present invention relates to the field of unmanned driving technology, and in particular to a method and device for monitoring the consistency of braking force response of an unmanned vehicle. Background Art

[0002] Autonomous vehicles are a type of intelligent vehicle that rely on an in-vehicle computer-based intelligent driver's control system to achieve autonomous operation. For example, in relevant scenarios, the autonomous vehicle's control computer can detect road conditions using sensors on the vehicle and determine the vehicle's current collision risk based on this information, thereby decelerating the vehicle if a collision risk exists. Autonomous vehicles are the future trend of intelligent vehicles. The autonomous driving control system controls steering, driving, and braking to ensure vehicle safety.

[0003] Vehicle braking performance is a very important vehicle safety performance, and the braking response time also needs to be accurately monitored. This is because there is actually a certain amount of time from the driver stepping on the brake pedal to the vehicle braking. If this period is too long, or due to mechanical, hardware or software failures, it may not be able to respond normally to the expected braking deceleration of the unmanned driving control system, which will lead to untimely braking and safety problems. Summary of the Invention

[0004] In view of this, it is necessary to provide a method and device for monitoring the consistency of the braking force response of an unmanned vehicle to solve the technical problem in the existing technology that the braking system cannot normally respond to the expected braking deceleration of the unmanned driving control system due to long response time or software and hardware failure, resulting in untimely braking.

[0005] To solve the above technical problems, in a first aspect, the present invention provides a method for monitoring the consistency of braking force response of an unmanned vehicle, comprising:

[0006] Determining a corresponding target braking force according to the target braking deceleration at each moment, and determining a target response time required for the service brake system to respond to the target braking force;

[0007] determining a preselected target braking force affecting the actual theoretical braking force at any moment based on the target response time, and determining the actual theoretical braking force at any moment based on the preselected target braking force;

[0008] At least one difference evaluation value between the actual braking force at each moment and the actual theoretical braking force is determined, and if all the difference evaluation values ​​are within corresponding normal critical thresholds, it is determined that the working state of the service brake system is normal.

[0009] In some possible implementations, determining the corresponding target braking force according to the target braking deceleration at each moment includes:

[0010] Determine the real-time mass of the vehicle based on the vehicle's wheel load and the slope of the road on which the vehicle is located;

[0011] The target braking deceleration received by the service braking system at multiple consecutive moments is obtained, and the target braking force at each moment is determined based on the target braking deceleration at each moment and the real-time mass of the vehicle.

[0012] In some possible implementations, determining a target response time required for the service brake system to respond to the target braking force specifically includes:

[0013] Determine the response time required for the vehicle's target braking force to jump from zero to a preset actual braking force, and obtain the linear relationship between the response time and braking force of the service brake system using the least squares method;

[0014] According to the linear relationship between the response time and braking force of the service brake system, the unit response time required to respond to the unit braking force is determined;

[0015] The target response time required for the service brake system to respond to the target braking force at any moment is determined according to the unit response time and a predetermined safety factor.

[0016] In some possible implementations, determining, based on the target response time, a preselected target braking force that affects the actual theoretical braking force at any moment specifically includes:

[0017] Obtaining a first target response time required for the service brake system to respond to the corresponding target braking force at the first moment;

[0018] Determine the update period of the target braking deceleration;

[0019] If the product of the first moment and the update period added to the first target response time is less than the product of the second moment and the update period, it is determined that the target braking force at the first moment has an impact on the actual theoretical braking force at the second moment, and the target braking force at the first moment is used as the preselected target braking force; wherein the first moment is not greater than the second moment;

[0020] If the product of the first moment and the update period added to the first target response time is not less than the product of the second moment and the update period, it is determined that the target braking force at the first moment has no effect on the actual theoretical braking force at the second moment.

[0021] In some possible implementations, determining the actual theoretical braking force at any moment based on the preselected target braking force specifically includes:

[0022] All preselected target braking forces are obtained, a maximum value among the preselected target braking forces is extracted as the actual theoretical maximum braking force, and a minimum value among the preselected target braking forces is extracted as the actual theoretical minimum braking force.

[0023] In some possible implementations, the difference evaluation value is a value related to the variance; and determining at least one difference evaluation value between the actual braking force at each moment and the actual theoretical braking force specifically includes:

[0024] The actual braking force at each moment is determined based on the brake caliper hydraulic cylinder pressure, the contact area between the brake caliper and the brake disc, and the friction coefficient between the brake caliper and the brake disc.

[0025] A first variance is determined based on the square of the difference between the actual braking force at each moment and the actual maximum theoretical braking force; a second variance is determined based on the square of the difference between the actual braking force at each moment and the actual minimum theoretical braking force; a first variance average and a first variance maximum of the first variance, as well as a second variance average and a second variance maximum of the second variance are determined.

[0026] In some possible implementations, if all the difference evaluation values ​​are within the corresponding normal critical thresholds, then it is determined that the working state of the service brake system is normal, specifically including:

[0027] If the maximum value of the first variance is not greater than the preset first variance normal critical threshold, the maximum value of the second variance is not greater than the preset second variance normal critical threshold, the average value of the first variance is not greater than the preset first variance average normal critical threshold, and the average value of the second variance is not greater than the preset second variance average normal critical threshold, it is determined that the service brake system is in normal working condition.

[0028] In a second aspect, the present invention further provides a device for monitoring the braking force response consistency of an unmanned vehicle, comprising:

[0029] a response time analysis module, which determines a corresponding target braking force according to the target braking deceleration at each moment, and determines a target response time required for the service brake system to respond to the target braking force;

[0030] an actual theoretical braking force analysis module, which determines a preselected target braking force that affects the actual theoretical braking force at any moment according to the target response time, and determines the actual theoretical braking force at any moment according to the preselected target braking force;

[0031] The actual braking force offset analysis module determines at least one difference evaluation value between the actual braking force and the actual theoretical braking force at each moment, and if all the difference evaluation values ​​are within the corresponding normal critical thresholds, it is determined that the working state of the service brake system is normal.

[0032] In a third aspect, an embodiment of the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the method for monitoring the consistency of the braking force response of an unmanned vehicle as described in the embodiment of the first aspect of the present invention are implemented.

[0033] In a fourth aspect, an embodiment of the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for monitoring the consistency of the braking force response of an unmanned vehicle as described in the embodiment of the first aspect of the present invention are implemented.

[0034] The beneficial effect of adopting the above embodiment is as follows: the method for monitoring the consistency of the braking force response of an unmanned vehicle provided by the present invention obtains the braking response characteristics of the service braking system and calculates the target response time corresponding to each target braking deceleration in real time. The target response time is used to determine the influence of the target braking force at each previous moment on the actual braking force at each subsequent moment, so as to determine the deviation between the actual theoretical braking force and the actual braking force. By obtaining the maximum value and the cumulative average value of the deviation, the interference or error caused by excessive single braking force deviation is avoided, which can greatly improve the accuracy and real-time performance of the braking force response monitoring of the service braking system, and improve the safety of the vehicle under unmanned driving conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A schematic flow chart of an embodiment of a method for monitoring the consistency of braking force response of an unmanned vehicle provided by the present invention;

[0037] Figure 2 A schematic diagram of an embodiment of a method for determining a corresponding target braking force according to a target braking deceleration provided by the present invention;

[0038] Figure 3 A schematic flow chart of an embodiment of a method for determining a target response time required for a target braking force provided by the present invention;

[0039] Figure 4A flow chart of an embodiment of a method for determining whether the target braking force at each previous moment affects the actual braking force at each subsequent moment provided by the present invention;

[0040] Figure 5 A schematic structural diagram of an embodiment of determining at least one difference evaluation value between actual braking force and actual theoretical braking force provided by the present invention;

[0041] Figure 6 A schematic structural diagram of an embodiment of a device for monitoring the braking force response consistency of an unmanned vehicle provided by the present invention;

[0042] Figure 7 This is a schematic structural diagram of an embodiment of the device for monitoring the braking force response consistency of an unmanned vehicle provided by the present invention. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0044] Some of the blocks shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0045] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0046] Braking is an important guarantee for vehicle safety, but the service braking system may not be able to respond normally to the expected braking deceleration of the unmanned driving control system due to possible mechanical, hardware or software failures.

[0047] Therefore, embodiments of the present invention provide a method and device for monitoring the braking force response consistency of an unmanned vehicle. These methods monitor the consistency between the actual braking force response of the service brake system and the expected target braking force in real time. If the consistency is consistent, the system is operating normally. If the inconsistency is detected, the vehicle is immediately stopped to prevent safety accidents such as failure to brake or over-braking during unmanned operation. The device also prompts the driver to inspect and repair the service brake system. These are described below.

[0048] Figure 1 A flow chart of an embodiment of a method for monitoring the braking force response consistency of an unmanned vehicle provided by the present invention is shown in FIG. Figure 1 As shown, the method for monitoring the consistency of braking force response of an unmanned vehicle includes:

[0049] Step S100: determining a corresponding target braking force according to the target braking deceleration at each moment, and determining a target response time required for the service brake system to respond to the target braking force;

[0050] Step S200: determining a preselected target braking force that affects the actual theoretical braking force at any moment based on the target response time, and determining the actual theoretical braking force at any moment based on the preselected target braking force;

[0051] Step S300: Determine at least one difference evaluation value between the actual braking force at each moment and the actual theoretical braking force. If all the difference evaluation values ​​are within the corresponding normal critical thresholds, it is determined that the working state of the service brake system is normal.

[0052] It is understood that braking deceleration refers to a vehicle's ability to rapidly reduce its speed until it comes to a stop while driving, and is the most basic metric for evaluating a vehicle's braking performance. It can be understood as: the braking distance required for a vehicle to stop after braking at a certain initial velocity, or the deceleration required for a vehicle to stop after braking at a certain initial velocity, or the vehicle's resistance to thermal degradation during continuous braking at high speeds or on long slopes. Braking force refers to the inertial force of a vehicle during deceleration or braking. Due to the inertia of the vehicle, the sliding friction between the road surface and the vehicle can prevent the vehicle's inertia. Braking is essentially braking, and braking force is the maximum rolling friction. Because friction decreases when rolling to sliding, the maximum rolling friction is greater than the sliding friction. In this embodiment, the target braking force refers to the braking force required to achieve the target deceleration requirement. The braking force response time refers to the entire braking process from the moment the brake pedal is depressed to the moment braking is complete.

[0053] Due to the existence of response time, the target braking force at the previous moments has an impact on the actual braking force at the subsequent moments. Therefore, in this embodiment, it is determined whether the target braking force at the previous moments has an impact on the actual theoretical braking force at the subsequent moments based on the required target response time of the target braking force at each moment, so as to determine the actual theoretical braking force at the subsequent moments.

[0054] Compared with the prior art, the method of this embodiment calculates the target response time corresponding to each target braking deceleration in real time by obtaining the braking response characteristics of the service brake system, and determines the influence of the target braking force at each previous moment on the actual braking force at each subsequent moment through the target response time, so as to determine the deviation between the actual theoretical braking force and the actual braking force. By obtaining the maximum value and the cumulative average value of the deviation, the interference or error caused by a single braking force deviation is avoided, which can greatly improve the accuracy and real-time performance of the monitoring of the response braking force of the service brake system. The consistency between the actual response braking force of the service brake system and the expected target braking force can be monitored in real time. If they are consistent, the system is working normally. If there is any inconsistency, the vehicle should be stopped immediately to prevent the vehicle from failing to brake or over-braking in unmanned driving conditions, and the driver is prompted to inspect the service brake system, thereby improving the safety of the vehicle in unmanned driving conditions.

[0055] Based on the above embodiments, as a preferred implementation, Figure 2 As shown in , in step S100, determining the corresponding target braking force according to the target braking deceleration at each moment specifically includes:

[0056] Step S111: Determine the real-time mass of the vehicle based on the wheel load of the vehicle and the slope of the road on which the vehicle is located. Perform classical mechanics analysis on the vehicle:

[0057]

[0058] In the above formula, F i is the wheel load on the i-th suspension of the vehicle, obtained by a force sensor mounted on the suspension. i∈[1,n], where n is the total number of suspensions on the vehicle. g is the acceleration due to gravity, m is the vehicle's real-time mass, and θ is the angle between the road surface and the horizontal plane, obtained by an inclination sensor mounted on the vehicle body.

[0059] From the above formula, we can see that the real-time mass of the vehicle is:

[0060]

[0061] Step S112: Obtain the target braking decelerations received by the service braking system at multiple consecutive moments. Record and store the target braking decelerations sent by the unmanned control system to the service braking system for the most recent k consecutive moments. The target braking deceleration at the kth moment is the braking deceleration at the current moment, the target braking deceleration at the k-1th moment is the braking deceleration at the previous moment, and so on. The target braking decelerations for the most recent k consecutive moments are dynamically updated and stored.

[0062] Step S113: Determine the target braking force at each moment based on the target braking deceleration at each moment and the real-time mass of the vehicle. The target braking force at each moment is equal to the braking deceleration speed multiplied by the real-time mass of the vehicle.

[0063] F target (j) = m*a target (j)

[0064] In the above formula, F target (j) is the calculated value of the target braking force of the unmanned control system at time j; a target (j) is the target deceleration at time j recorded and stored by the unmanned control system, and j∈[1,k].

[0065] Based on the above embodiments, as a preferred implementation, Figure 3 As shown in the step S100, determining the target response time required for the service brake system to respond to the target braking force specifically includes:

[0066] Step S121: Determine the response time required for the target braking force of the vehicle to jump from zero step to a preset actual braking force, and obtain the linear relationship between the response time and the braking force of the service brake system according to the least squares method.

[0067] In this embodiment, a test bench is used to calculate the time required for the service brake system to respond to a unit braking force. The test bench is used to directly step the target braking force from 0 to τ*ΔF, and the response time t required for the service brake system to respond to the actual braking force of τ*ΔF is recorded. τ .

[0068] The linear relationship between the response time and braking force of the service brake system is calculated using the least squares method:

[0069] t(F)=γ*F+b

[0070] In the above formula, t(F) is the response time required for the braking force of the service brake system to jump from 0 to F, F is the actual braking force of the service brake on the test bench; γ is the least squares coefficient 1; b is the least squares coefficient 2.

[0071] According to the linear relationship between the response time and braking force of the service brake system, the unit response time required to respond to unit braking force is determined.

[0072] Based on the above linear relationship, τ∈[1,τ max ],and F max The maximum braking force available to the service brake system.

[0073] According to (τ*ΔF, t τ ), using the least squares method we can know that:

[0074]

[0075] Among them: average value for:

[0076]

[0077] Furthermore, we know that γ and b are:

[0078]

[0079] Furthermore, it can be seen that the unit response time required for the service brake system to respond to a unit braking force is:

[0080]

[0081] Where t(1) is the time required for the service brake system to respond to unit braking force.

[0082] Step S122: Determine the target response time required for the service brake system to respond to the target braking force at any moment according to the unit response time and a predetermined safety factor.

[0083] The target braking force response time at each moment is equal to the target braking force multiplied by the unit response time required for the service brake system to respond to the unit braking force, multiplied by a safety factor to eliminate interference and response error factors, that is:

[0084] t(F target (j))=F(j)*t(1)*δ

[0085] In the above formula, t(F target (j)) is the target braking force F of the service brake system in response to the unmanned control system at time j target (j) Target response time required; F target (j) is the target braking force of the unmanned system at time j; δ is the safety factor. The response time becomes longer due to system interference or response error, and δ>1.

[0086] Based on the above embodiments, as a preferred implementation, Figure 4 As shown in FIG, in step S200, determining the preselected target braking force that affects the actual theoretical braking force at any moment according to the target response time specifically includes:

[0087] Step S210: Obtain the first target response time t(F) required for the service brake system to respond to the corresponding target braking force at the first moment j0. target (j0));

[0088] Determine the update period of the target braking deceleration;

[0089] If the product of the first moment j0 and the update period Δt equals the first target response time t(F target (j0)) is less than the product of the second moment j and the update period Δt, it is determined that the target braking force at the first moment j0 has an impact on the actual theoretical braking force at the second moment j, and the target braking force at the first moment j0 is used as the preselected target braking force; if the product of the first moment j0 and the update period Δt is equal to the first target response time t(F target (j0)) is not less than the product of the second moment j and the update period △t, then it is judged that the target braking force at the first moment j0 has no effect on the actual theoretical braking force at the second moment j, wherein the first moment j0 is not greater than the second moment j.

[0090] Based on the required response time of the target braking force at each moment, it is determined whether the target braking force at each moment before affects the actual braking force at each moment after. The determination method is that the actual braking force after the moment when the braking deceleration record at a certain moment before is stored plus the time required for the corresponding braking force response can be affected by the braking force at the previous moment; the actual braking force before the moment when the deceleration record at a certain moment before is stored plus the time required for the corresponding braking force response is not affected by the braking force at the previous moment. That is:

[0091]

[0092] In the above formula, β(j0) is the influence factor of the target braking force at the first moment j0 on the actual theoretical braking force at the second moment j, where 0 indicates no influence and 1 indicates influence; Δt is the update period of the target braking deceleration of the unmanned driving control system.

[0093] In some possible implementations, determining the actual theoretical braking force at any moment based on the preselected target braking force specifically includes:

[0094] Step S220: Acquire all preselected target braking forces, extract the maximum value among the preselected target braking forces as the actual theoretical maximum braking force, and extract the minimum value among the preselected target braking forces as the actual theoretical minimum braking force.

[0095] The service brake system's response time affects the maximum and minimum targets for the actual theoretical braking force at each moment. Since the actual theoretical braking force and target braking force at each moment vary in magnitude, potentially significantly or slightly, the maximum and minimum values ​​that may affect the actual theoretical braking force at that moment are determined based on the target braking forces at all previous moments. That is:

[0096]

[0097] In the above formula, F max (j) is the actual theoretical maximum braking force of the service brake system in the jth response; F min (j) The actual theoretical minimum braking force of the service brake system at time j.

[0098] Based on the above embodiment, as a preferred implementation, in step S300, Figure 5 As shown in , in this embodiment, the difference evaluation value is a value related to the variance; the determining of at least one difference evaluation value between the actual braking force at each moment and the actual theoretical braking force specifically includes:

[0099] Step S311: Determine the actual braking force at each moment based on the brake caliper hydraulic cylinder pressure, the contact area between the brake caliper and the brake disc, and the friction coefficient between the brake caliper and the brake disc. Calculate the actual total braking force of the vehicle at each moment using the brake caliper hydraulic cylinder pressure. The actual total braking force of the vehicle at each moment is equal to the sum of the brake caliper hydraulic cylinder pressures multiplied by the contact area between the brake caliper and the brake disc, multiplied by the friction coefficient. Specifically:

[0100]

[0101] In the above formula, F act (j) is the actual total braking force of the vehicle at time j; p(j) i is the pressure of the i-th brake caliper hydraulic cylinder at time j, obtained by the pressure sensor installed in the hydraulic cylinder; u i is the friction coefficient between the i-th brake caliper and the brake disc, a fixed parameter; s i The contact area between the i-th brake caliper and the brake disc, a fixed value.

[0102] Step S312: Determine a first variance based on the square of the difference between the actual braking force at each moment and the actual maximum theoretical braking force; determine a second variance based on the square of the difference between the actual braking force at each moment and the actual minimum theoretical braking force.

[0103] Calculate the variance of the actual braking force of the service brake system at each moment and the actual maximum and minimum theoretical braking force. This variance is equal to the square of the difference between the actual braking force of the service brake system at each moment and the actual maximum and minimum theoretical braking force, that is:

[0104]

[0105] In the above formula, ΔF max (j) is the first variance, F max (j) is the actual theoretical maximum braking force at time j, F act (j) is the actual braking force at time j; ΔF min (j) is the second variance, F min (j) is the actual theoretical minimum braking force at time j.

[0106] Step S313: Determine a first variance mean value and a first variance maximum value of the first variance, and a second variance mean value and a second variance maximum value of the second variance.

[0107]

[0108] In the above formula, where: ΔF maxmax is the maximum value of the variance between the actual braking force of the service brake system and the actual theoretical braking force (i.e., the first maximum variance); ΔF minmin The maximum value of the variance between the actual braking force of the service brake system and the minimum value of the actual theoretical braking force (the second maximum variance); It is the cumulative average of the variance between the actual braking force of the service brake system and the actual theoretical maximum braking force; The cumulative average of the variance between the actual braking force of the vehicle's braking system and the actual theoretical minimum braking force.

[0109] In other embodiments besides this embodiment, the difference evaluation value may also be one or more of the following: standard deviation, median absolute deviation, covariance, correlation coefficient, and determination coefficient.

[0110] Based on the above embodiment, as a preferred implementation manner, if all the difference evaluation values ​​are within the corresponding normal critical thresholds, then it is determined that the working state of the service brake system is normal, specifically including:

[0111] If the maximum value of the first variance is not greater than the preset first variance normal critical threshold, the maximum value of the second variance is not greater than the preset second variance normal critical threshold, the average value of the first variance is not greater than the preset first variance average normal critical threshold, and the average value of the second variance is not greater than the preset second variance average normal critical threshold, it is determined that the service brake system is in normal working condition.

[0112] The normality of the service brake system's response to the target braking deceleration is determined based on the maximum value and the average value of the deviation. maxmax ≤ΔF maxmax1 And ΔF minmin ≤ΔF minmin1 and and The service brake system works normally and can respond normally to the target braking deceleration sent by the unmanned control system; otherwise, if ΔF maxmax >ΔF maxmax1 or ΔF minmin >ΔF minmin1 or or The braking system is malfunctioning, and there is a large deviation in the response to the target braking deceleration speed sent by the unmanned driving control system. There is a fault in which the vehicle's braking deceleration is inconsistent with expectations. The unmanned driving control system stops working and prompts that there is a fault in the vehicle's service brakes, requesting repair.

[0113] Where ΔF maxmax1 ΔF is the first normal critical threshold of the variance between the actual braking force of the service braking system and the actual theoretical maximum braking force; minmin1 A second variance normal critical threshold value of the variance between the actual braking force of the service brake system and the actual theoretical minimum braking force; The normal critical threshold value (first variance average normal critical threshold value) of the cumulative average variance of the actual braking force of the service brake system and the actual theoretical maximum braking force; is the normal critical threshold value of the cumulative average value of the variance between the actual braking force of the service braking system and the actual theoretical minimum braking force (the second variance average value normal critical threshold value). maxmax1 , ΔF minmin1 Both greater than

[0114] In order to better implement the unmanned vehicle braking force response consistency monitoring method in the embodiment of the present invention, based on the unmanned vehicle braking force response consistency monitoring method, the embodiment of the present invention also provides an unmanned vehicle braking force response consistency monitoring device, such as Figure 6 As shown, the unmanned vehicle braking force response consistency monitoring device 600 includes:

[0115] The response time analysis module 601 determines a corresponding target braking force according to the target braking deceleration at each moment, and determines a target response time required for the service brake system to respond to the target braking force;

[0116] The actual theoretical braking force analysis module 602 determines a preselected target braking force that affects the actual theoretical braking force at any moment based on the target response time, and determines the actual theoretical braking force at any moment based on the preselected target braking force;

[0117] The actual braking force offset analysis module 603 determines at least one difference evaluation value between the actual braking force and the actual theoretical braking force at each moment. If all the difference evaluation values ​​are within the corresponding normal critical thresholds, it is determined that the working state of the vehicle braking system is normal.

[0118] The unmanned vehicle braking force response consistency monitoring device 600 provided in the above embodiment can implement the technical solution described in the above embodiment of the unmanned vehicle braking force response consistency monitoring method. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above embodiment of the unmanned vehicle braking force response consistency monitoring method, which will not be repeated here.

[0119] like Figure 7 As shown, the present invention also provides an electronic device 700. The electronic device 700 includes a processor 701, a memory 702 and a display 703. Figure 7 Only some of the components of the electronic device 700 are shown, but it should be understood that it is not required to implement all of the shown components, and more or fewer components may be implemented instead.

[0120] In some embodiments, the memory 702 may be an internal storage unit of the electronic device 700, such as a hard disk or memory of the electronic device 700. In other embodiments, the memory 702 may also be an external storage device of the electronic device 700, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 700.

[0121] Furthermore, the memory 702 may include both an internal storage unit of the electronic device 700 and an external storage device. The memory 702 is used to store application software installed in the electronic device 700 and various data.

[0122] In some embodiments, the processor 701 can be a central processing unit (CPU), a microprocessor, or other data processing chip, used to run program codes or process data stored in the memory 702, such as the self-driving car braking force response consistency monitoring method in the present invention.

[0123] In some embodiments, the display 703 can be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. The display 703 is used to display information on the electronic device 700 and to display a visual user interface. Components 701-703 of the electronic device 700 communicate with each other via a system bus.

[0124] In some embodiments of the present invention, when the processor 701 executes the autonomous vehicle braking force response consistency monitoring program in the memory 702, the following steps may be implemented:

[0125] Determining a corresponding target braking force according to the target braking deceleration at each moment, and determining a target response time required for the service brake system to respond to the target braking force;

[0126] determining a preselected target braking force affecting the actual theoretical braking force at any moment based on the target response time, and determining the actual theoretical braking force at any moment based on the preselected target braking force;

[0127] At least one difference evaluation value between the actual braking force at each moment and the actual theoretical braking force is determined, and if all the difference evaluation values ​​are within corresponding normal critical thresholds, it is determined that the working state of the service brake system is normal.

[0128] It should be understood that, when the processor 701 executes the unmanned vehicle braking force response consistency monitoring program in the memory 702 , in addition to the above functions, it can also implement other functions. For details, please refer to the description of the corresponding method embodiment above.

[0129] Furthermore, the embodiment of the present invention does not specifically limit the type of the electronic device 700 mentioned. The electronic device 700 may be a portable electronic device such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, or a laptop computer. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with iOS, Android, Microsoft, or other operating systems. The above-mentioned portable electronic devices may also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 700 may not be a portable electronic device, but a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0130] Accordingly, an embodiment of the present application also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, the steps or functions of the unmanned vehicle braking force response consistency monitoring method provided by the above-mentioned method embodiments can be implemented.

[0131] Those skilled in the art will appreciate that all or part of the process steps of the above-described embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0132] The above is a detailed introduction to the method and device for monitoring the consistency of the braking force response of an unmanned vehicle provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for monitoring the consistency of braking force response of an unmanned vehicle, characterized in that: include: Determining a corresponding target braking force according to the target braking deceleration at each moment, and determining a target response time required for the service brake system to respond to the target braking force; determining a preselected target braking force affecting the actual theoretical braking force at any moment based on the target response time, and determining the actual theoretical braking force at any moment based on the preselected target braking force; determining at least one difference evaluation value between the actual braking force at each moment and the actual theoretical braking force, and determining that the operating state of the service brake system is normal if all the difference evaluation values ​​are within corresponding normal critical thresholds; Determining a target response time required for the service brake system to respond to the target braking force specifically includes: Determine the response time required for the vehicle's target braking force to jump from zero to a preset actual braking force, and obtain the linear relationship between the response time and braking force of the service brake system using the least squares method; According to the linear relationship between the response time and braking force of the service brake system, the unit response time required to respond to the unit braking force is determined; determining a target response time required for the service brake system to respond to a target braking force at any moment based on the unit response time and a predetermined safety factor; Determining, based on the target response time, a preselected target braking force that affects the actual theoretical braking force at any moment specifically includes: Obtaining a first target response time required for the service brake system to respond to the corresponding target braking force at the first moment; Determine the update period of the target braking deceleration; If the product of the first moment and the update period added to the first target response time is less than the product of the second moment and the update period, it is determined that the target braking force at the first moment has an impact on the actual theoretical braking force at the second moment, and the target braking force at the first moment is used as the preselected target braking force; wherein the first moment is not greater than the second moment; If the product of the first moment and the update period added to the first target response time is not less than the product of the second moment and the update period, it is determined that the target braking force at the first moment has no effect on the actual theoretical braking force at the second moment.

2. The method for monitoring the braking force response consistency of an unmanned vehicle according to claim 1, characterized in that: Determining the corresponding target braking force according to the target braking deceleration at each moment includes: Determine the real-time mass of the vehicle based on the vehicle's wheel load and the slope of the road on which the vehicle is located; The target braking deceleration received by the service braking system at multiple consecutive moments is obtained, and the target braking force at each moment is determined based on the target braking deceleration at each moment and the real-time mass of the vehicle.

3. The method for monitoring the braking force response consistency of an unmanned vehicle according to claim 1, wherein: Determining the actual theoretical braking force at any moment based on the preselected target braking force specifically includes: All preselected target braking forces are obtained, a maximum value among the preselected target braking forces is extracted as the actual theoretical maximum braking force, and a minimum value among the preselected target braking forces is extracted as the actual theoretical minimum braking force.

4. The method for monitoring the braking force response consistency of an unmanned vehicle according to claim 3, wherein: The difference evaluation value is a value related to the variance; and determining at least one difference evaluation value between the actual braking force at each moment and the actual theoretical braking force specifically includes: The actual braking force at each moment is determined based on the brake caliper hydraulic cylinder pressure, the contact area between the brake caliper and the brake disc, and the friction coefficient between the brake caliper and the brake disc. A first variance is determined based on the square of the difference between the actual braking force at each moment and the actual maximum theoretical braking force; a second variance is determined based on the square of the difference between the actual braking force at each moment and the actual minimum theoretical braking force; a first variance average and a first variance maximum of the first variance, as well as a second variance average and a second variance maximum of the second variance are determined.

5. The method for monitoring the consistency of braking force response of an unmanned vehicle according to claim 4, characterized in that: If all the difference evaluation values ​​are within the corresponding normal critical thresholds, then it is determined that the working state of the service brake system is normal, specifically including: If the maximum value of the first variance is not greater than the preset first variance normal critical threshold, the maximum value of the second variance is not greater than the preset second variance normal critical threshold, the average value of the first variance is not greater than the preset first variance average normal critical threshold, and the average value of the second variance is not greater than the preset second variance average normal critical threshold, it is determined that the service brake system is in normal working condition.

6. A device for monitoring the braking force response consistency of an unmanned vehicle, characterized in that: include: a response time analysis module, which determines a corresponding target braking force according to the target braking deceleration at each moment, and determines a target response time required for the service brake system to respond to the target braking force; an actual theoretical braking force analysis module, which determines a preselected target braking force that affects the actual theoretical braking force at any moment according to the target response time, and determines the actual theoretical braking force at any moment according to the preselected target braking force; an actual braking force deviation analysis module, which determines at least one difference evaluation value between the actual braking force and the actual theoretical braking force at each moment, and determines that the operating state of the service brake system is normal if all the difference evaluation values ​​are within corresponding normal critical thresholds; Determining a target response time required for the service brake system to respond to the target braking force specifically includes: Determine the response time required for the vehicle's target braking force to jump from zero to a preset actual braking force, and obtain the linear relationship between the response time and braking force of the service brake system using the least squares method; According to the linear relationship between the response time and braking force of the service brake system, the unit response time required to respond to the unit braking force is determined; determining a target response time required for the service brake system to respond to a target braking force at any moment based on the unit response time and a predetermined safety factor; Determining, based on the target response time, a preselected target braking force that affects the actual theoretical braking force at any moment specifically includes: Obtaining a first target response time required for the service brake system to respond to the corresponding target braking force at the first moment; Determine the update period of the target braking deceleration; If the product of the first moment and the update period added to the first target response time is less than the product of the second moment and the update period, it is determined that the target braking force at the first moment has an impact on the actual theoretical braking force at the second moment, and the target braking force at the first moment is used as the preselected target braking force; wherein the first moment is not greater than the second moment; If the product of the first moment and the update period added to the first target response time is not less than the product of the second moment and the update period, it is determined that the target braking force at the first moment has no effect on the actual theoretical braking force at the second moment.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method for monitoring the consistency of braking force response of an unmanned vehicle as claimed in any one of claims 1 to 5 are implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for monitoring the consistency of braking force response of an unmanned vehicle as claimed in any one of claims 1 to 5 are implemented.

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