Test bench and test method for brake response time of EMB assembly

Abstract

The invention discloses a test bench and a test method for brake response time of an EMB assembly, and the test bench comprises a caliper which is provided with a filler block, the caliper can drive the filler block to move, and the filler block can move to be close to a brake disc so as to clamp the brake disc; the interior of the environment bin is used for providing environment simulation conditions required by testing for the calipers; the fixing tool is arranged in the environment bin, and the fixing tool is used for installing and fixing calipers; the vibration mechanism is used for driving the fixing tool to vibrate so as to drive the calipers to vibrate; the detection mechanism comprises a plurality of force sensors, the plurality of force sensors are arranged between the contact parts of the calipers and the filler block, and when the brake disc is clamped by the filler block, the force sensors can detect the pressure of the calipers acting on the filler block. The brake response time can be accurately calculated, and the reliability and authenticity of the test are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brake test equipment, in particular to a test bench and test method for brake response time of an EMB assembly. BACKGROUND

[0002] The electro-mechanical brake (EMB) technology is an important technology in the field of automobile brake systems. The EMB system discards complex components such as brake fluid, hydraulic pipeline and vacuum booster, and directly drives the EMB actuator assembly installed on each wheel to generate braking force by converting the brake pedal signal into an electrical signal. A typical EMB assembly mainly includes a main structure, a pair of brake pads, a screw drive mechanism for converting rotary motion into linear motion, and a motor actuator.

[0003] At present, the test of the brake response time of the EMB assembly is mostly carried out in an ideal laboratory environment. The common test bench usually only sets the EMB caliper assembly for testing under the condition of no external interference. Although this method can measure the basic response performance of the EMB assembly in a static and ideal state, there is a significant difference between the test results and the actual performance of the EMB assembly in a real driving environment, which leads to the fact that the test data cannot comprehensively and truly reflect the actual braking performance of the EMB assembly on the whole vehicle. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes a test bench for brake response time of an EMB assembly, which can accurately calculate the brake response time and improve the reliability and authenticity of the test.

[0005] The present application also proposes a test method for the test bench for brake response time of the above-mentioned EMB assembly.

[0006] The test bench for brake response time of an EMB assembly according to the first aspect of the present application comprises: a caliper provided with a pad, the caliper being capable of driving the pad to move, the pad being capable of moving close to a brake disc to clamp the brake disc; an environment bin, the inside of the environment bin being used to provide the caliper with the environment simulation conditions required for testing; a fixing tool, the fixing tool being arranged inside the environment bin and being used to install and fix the caliper; a vibration mechanism, the vibration mechanism being used to drive the fixing tool to vibrate so as to drive the caliper to vibrate; and a detection mechanism, the detection mechanism comprising a plurality of force sensors, the plurality of force sensors being arranged between the contact parts of the caliper and the pad, the force sensors being capable of detecting the pressure of the caliper acting on the pad when the pad clamps the brake disc.

[0007] According to the test bench and test method for brake response time of the EMB assembly, at least the following beneficial effects are achieved: 1. The environment bin can simulate the temperature and humidity conditions in the actual driving environment, and the vibration mechanism can simulate the road bumping amplitude conditions, so that the test results are closer to the brake performance of the EMB assembly on the actual vehicle, the problem of disconnection between the test in the existing external interference-free environment and the actual environment is solved, the measured brake response time is closer to the actual working condition, and the data is more reliable.

[0008] 2. The multiple force sensors are arranged, the caliper is driven by the clamping part to clamp the pad against the brake disc under the influence of the external environment in the simulated driving environment, the detection mechanism directly measures the pressure of the caliper acting on the pad by using the multiple force sensors, the clamping force can be tested under the influence of the driving environment, the environmental condition factor is considered, the authenticity of the clamping force test data is improved, and therefore, the brake response time can be accurately calculated by analyzing the collected clamping force data, and the reliability and authenticity of the test are improved.

[0009] According to some embodiments of the application, the environment cabin is arranged with an air conditioning device, a spraying device and a blowing device, the air conditioning device is used for adjusting the temperature of the environment cabin, the spraying device is used for spraying water, snow and ice blocks to the caliper to simulate rain, snow and hail environment conditions, and the blowing device is used for blowing dust and stones to the caliper to simulate the dust and stone conditions in the process of automobile driving.

[0010] Beneficially, the air conditioning device can change the temperature of the environment cabin, so that the environment bin can simulate low temperature and high temperature environment conditions, and the EMB assembly can be tested at different temperatures.

[0011] The spraying device can spray water, snow and ice blocks to the caliper to simulate rain, snow and hail environment conditions, and the blowing device can blow dust to the caliper, so that the EMB assembly can be tested in a single environment or a composite and complex environment, the brake response of the EMB assembly in different environments is comprehensively tested, various actual driving scenes are ensured to be covered, and the comprehensiveness and applicability of the test are improved.

[0012] According to some embodiments of the application, the vibration mechanism is a spring, one end of the spring is connected to the fixed tooling, and the other end is connected to the workbench in the environment bin, and the spring can drive the caliper to vibrate up and down to simulate the road surface in different bumping conditions in the process of automobile driving.

[0013] Beneficially: the application adopts a spring for the vibrating mechanism, which is simple in structure and low in cost, and the vibration characteristics of the spring can better simulate the up-down vibration generated when the automobile passes through a bumpy road, thereby providing the caliper with mechanical interference in line with actual working conditions, testing the braking response performance of the caliper under such dynamic conditions, making the test closer to actual road conditions, and enhancing the practicality and economy of the test.

[0014] According to the second aspect of the application, a test method is applied to a test bench for testing the braking response time of an EMB assembly, and the test method comprises the following steps: installing and fixing the caliper on the fixing tool; setting different environmental conditions of the environmental chamber and controlling the vibrating mechanism to generate different amplitudes of bumps to simulate various driving conditions; controlling the caliper to clamp the brake disc with the maximum clamping force under various driving conditions; synchronously collecting the clamping force of the caliper at a set frequency by the plurality of force sensors, and obtaining a plurality of relationship curves of the clamping force changing over time according to the clamping force of the caliper changing over time; extracting a relationship curve with the highest credibility from the plurality of relationship curves; and obtaining the response time of the caliper according to the relationship curve with the highest credibility.

[0015] According to the test method of the application, at least the following beneficial effects are achieved: The test method of the application measures the clamping force by each force sensor under simulated driving conditions to obtain a plurality of relationship curves of the clamping force changing over time, extracts a relationship curve with the highest credibility from the plurality of relationship curves, and obtains the response time of the caliper according to the relationship curve with the highest credibility, so that unreasonable clamping forces measured by each force sensor are excluded, and the accuracy of the final result is ensured, and the authenticity of the time response test is improved.

[0016] According to some embodiments of the application, extracting a relationship curve with the highest credibility from the plurality of relationship curves comprises: taking the intersection points of the plurality of relationship curves as segmentation points; obtaining the segmentation points of the plurality of relationship curves according to the slopes of the continuous points of the relationship curves; segmenting the plurality of relationship curves by the segmentation points to obtain a plurality of curve segments for each relationship curve; taking the most smooth curve segment as the relationship curve with the highest credibility according to the smoothness of the plurality of curve segments in the same time period; and obtaining the relationship curve with the highest credibility of the clamping force changing over time by fitting the relationship curve with the highest credibility.

[0017] The advantage of this invention is that by obtaining the smoothness of multiple curve segments in the same time period, fitting the curve segment with the highest credibility, and using the relationship curve with the highest credibility, it is possible to filter out curve segments with peaks and noise at the smallest granularity, select the high-quality data segments that best reflect the real braking process for fitting, and finally obtain a high-credibility relationship curve, thereby significantly improving the accuracy of response time calculation and anti-interference ability.

[0018] According to some embodiments of the present invention, obtaining the segmentation points of multiple relationship curves based on the slope of the continuous points of the relationship curve includes: setting a slope change threshold of the relationship curve; detecting the slope of the continuous points of the relationship curve; and if the slope difference between two adjacent continuous points of the relationship curve is greater than the slope change threshold, then determining the point with a significant slope change as a segmentation point.

[0019] The advantages are: the present invention objectively determines the segmentation point by setting a slope change threshold, transforming subjective experience judgment into a quantifiable and consistent algorithm standard, reducing human error, and improving the automation and repeatability of data analysis.

[0020] According to some embodiments of the present invention, the step of segmenting multiple relation curves by the segmentation point so that each relation curve obtains multiple curve segments includes: obtaining the time point of the clamping force corresponding to the relation curve according to the segmentation point, and dividing the relation curve into time periods by the time points; obtaining the curve segments corresponding to the time periods on multiple relation curves according to the time periods.

[0021] The advantage of this invention is that it obtains time points by segmentation points, and then obtains time periods by time points to obtain curve segments on the relationship curve. This ensures that multiple curves are aligned and fairly compared on the same time dimension, providing an accurate basis for subsequent smoothness evaluation of curve segments.

[0022] According to some embodiments of the present invention, the smoothest curve segment is selected as the curve segment with the highest reliability based on the smoothness of multiple curve segments in the same time period, including: uniformly sampling multiple curve segments respectively, obtaining multiple sampling points for each of the multiple curve segments; calculating the curvature of multiple sampling points for each curve segment, and then calculating the average value of the curvature of the multiple sampling points; and obtaining the minimum average curvature based on the magnitude of the average curvature of each curve segment.

[0023] The advantage is that this invention quantifies the smoothness of curve segments by calculating the average curvature, which is a mathematically rigorous evaluation method. The smaller the average curvature, the smoother the curve segment and the higher its reliability. Thus, the curve segments with the highest reliability are selected.

[0024] According to some embodiments of the present application, the method further comprises: obtaining the response time of the caliper under various driving conditions, and writing the response time into the vehicle system; setting a response threshold, and if the response time of the caliper is greater than the response threshold, the caliper needs to be braked in advance.

[0025] Beneficially, the present application sets a response threshold, and the vehicle system learns the environment of the vehicle through the sensing system of the vehicle, and then learns the response time of the EMB caliper. If the response time of the EMB caliper is greater than the response threshold, it means that the braking of the EMB caliper is slower in this environment, and it is necessary to brake in advance, which significantly improves the driving safety.

[0026] According to some embodiments of the present application, the method further comprises: setting different environmental conditions of the environment bin, and controlling the vibration mechanism to generate different jolt amplitudes to simulate various driving conditions, wherein the environmental conditions are temperature, rainy day, snowy day, hail and dust degree, or any combination of temperature, rainy day, snowy day, hail and dust degree, and each environmental condition needs to be tested for corresponding response time; and the vibration mechanism is a spring, and the number and size of the initial pressure applied to the spring are set to obtain different jolt amplitudes, and each setting of the number and size of the initial pressure needs to be tested for corresponding response time.

[0027] Beneficially, the present application can test the environmental conditions and vibration amplitudes in any combination, and requires independent testing of the braking response time for each combination, which can deeply evaluate the performance of the EMB assembly under the influence of single factor and composite factor.

[0028] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0030] Figure 1 FIG. 1 is a structural schematic diagram of an EMB assembly braking response time test bench and test method according to an embodiment of the present application; Figure 2 FIG. 2 is a flowchart of a test method according to an embodiment of the present application; Figure 3 FIG. 3 is a flowchart of obtaining the most reliable relationship curve of a test method according to an embodiment of the present application. Figure 4 A flow chart for determining a segment point of a test method; Figure 5 A flow chart for obtaining a curve segment of a test method; Figure 6 A flow chart for calculating a curvature of a test method; Figure 7 A graph of the relationship between the clamping force corresponding to two force sensors of a test method.

[0031] Reference numerals: 100-caliper, 110-pad, 120-environment bin, 130-spraying device, 140-blowing device, 150-spring, 160-power supply, 170-controller, 180-upper computer, 190-stand, 200-fixing block, 210-brake disc. DETAILED DESCRIPTION

[0032] Embodiments of the present application are described below in detail with reference to the accompanying drawings, in which the same or similar numerals indicate the same or similar elements or elements having the same or similar functions throughout the drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation on the present application.

[0033] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as a limitation on the present application. The device or element indicated is not necessarily constructed and operated in a particular orientation.

[0034] In the description of the present application, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If it is described as first and second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of indicated technical features.

[0035] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting, connecting and connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] A test bench and a test method for brake response time of an EMB assembly are described below according to an embodiment of the present application.

[0037] The present application aims to provide an embodiment of a test bench and a test method for brake response time of an EMB assembly.

[0038] The test bench for brake response time of an EMB assembly according to an embodiment of the present application, with reference to Figure 1 , comprises a caliper 100, an environment cabin 120, a fixing tool and a vibration mechanism.

[0039] The caliper 100 is provided with a pad 110, the caliper 100 can drive the pad 110 to move, and the pad 110 can move close to the brake disc 210 to clamp the brake disc 210.

[0040] It should be noted that the caliper 100 is connected with a power supply 160, the power supply 160 can supply power to the caliper 100, so that the caliper 100 realizes the brake function.

[0041] The controller 170 is connected with the caliper 100, and is used for receiving the control instruction of the upper computer 180, converting the control instruction into a motor control signal, and controlling the clamping force of the caliper 100 in real time.

[0042] The environment cabin 120 is internally used to provide the caliper 100 with the environment simulation conditions required for testing.

[0043] Specifically, the environment cabin is arranged with an air conditioning device, a spraying device 130 and a blowing device 140, the air conditioning device is used to adjust the temperature of the environment cabin, the spraying device 130 is used to spray water, snow and ice blocks to the caliper 100 to simulate the rain, snow and hail environment conditions, and the blowing device 140 is used to blow dust and stones to the caliper 100 to simulate the dust and stone conditions in the process of automobile driving.

[0044] By setting the air conditioning device, the air conditioning device can change the temperature of the environment cabin, so that the environment cabin 120 can simulate the low temperature and high temperature environment conditions, and the EMB assembly can be tested at different temperatures.

[0045] The controller 170 is electrically connected with the environment cabin 120, the upper computer 180 sends the control instruction to the controller 170, and simultaneously sends the control instruction to the air conditioning device, the spraying device 130 and the blowing device 140 to simulate the environment required for testing.

[0046] The fixing tool is arranged in the interior of the environment cabin 120, and is used to install and fix the caliper 100.

[0047] Specifically, the fixed tooling includes a vertical rod 190, a fixed block 200 connected with the vertical rod 190, the vertical rod 190 and the fixed block 200 are connected through bolts, the caliper 100 is fixed on the fixed block 200, and the brake disc 210 can be fixed on a workbench in the environmental bin 120.

[0048] The vibration mechanism is configured to drive the fixed tooling to vibrate to drive the caliper 100 to vibrate.

[0049] It can be understood that, by arranging the environmental bin 120 and the vibration mechanism, the environmental bin 120 can simulate the temperature and humidity conditions in the actual driving environment, and the vibration mechanism can simulate the road bumping amplitude conditions, so that the test result is closer to the braking performance of the EMB assembly on the actual vehicle, the problem that the test in the existing environment without external interference is disconnected with the real environment is solved, the measured braking response time is closer to the actual working condition, and the data is more reliable.

[0050] In some embodiments of the present application, the vibration mechanism is a spring 150, one end of the spring 150 is connected to the fixed tooling, the other end of the spring 150 is connected to the workbench in the environmental bin 120, and the spring 150 can drive the caliper 100 to vibrate up and down to simulate the road surface in different bumping conditions during automobile driving.

[0051] By adopting the spring 150 as the vibration mechanism, the structure is simple and the cost is low, the vibration characteristics of the spring 150 can better simulate the up-and-down vibration generated when the automobile passes through the bumping road surface, the caliper 100 is provided with mechanical interference conforming to the actual working condition, the braking response performance of the caliper 100 under the dynamic condition is tested, the test is closer to the actual road condition, and the practicality and economy of the test are enhanced.

[0052] It should be noted that the spring 150 can be detachably arranged, and springs 150 with different elastic coefficients or lengths can be replaced to simulate the vibration frequency and amplitude of different bumping road surfaces.

[0053] The detection mechanism includes a plurality of force sensors arranged between the contact part of the caliper 100 and the pad 110, and the force sensors can detect the pressure of the caliper 100 acting on the pad 110 when the pad 110 clamps the brake disc 210.

[0054] It can be understood that, in the simulated driving environment, the caliper 100 drives the pad 110 to clamp the brake disc 210 by using the clamping part under the influence of the external environment, meanwhile, the detection mechanism directly measures the pressure of the caliper 100 acting on the pad 110 by using the plurality of force sensors, so that the clamping force can be tested under the influence of the driving environment, the environmental condition factor is considered, the authenticity of the clamping force test data is improved, thereby, the braking response time can be accurately calculated by analyzing the collected clamping force data, and the reliability and authenticity of the test are improved.

[0055] It should be noted that the force sensor can be a strain gauge, and the force sensor is a prior art which will not be described here.

[0056] Further, the force sensor is connected with the host computer 180, and the force sensor transmits the piezoelectric signal to the host computer 180 when the pad 110 of the caliper 100 clamps the brake disc 210.

[0057] The application also provides a test method applied to a test bench for testing the brake response time of an EMB assembly including any one of the above. Figure 2 , comprising: Step S100, the caliper 100 is installed and fixed on the fixed tooling.

[0058] Step S200, different environmental conditions of the environmental chamber 120 are set, and the vibration mechanism is controlled to generate different amplitudes of jolts to simulate various driving conditions.

[0059] Step S300, under various driving conditions, the caliper 100 is controlled to clamp the brake disc 210 with the maximum clamping force.

[0060] Step S400, the plurality of force sensors synchronously collect the clamping force of the caliper 100 according to the set frequency, and according to the clamping force of the caliper 100 changing with time, a plurality of relationship curves of the clamping force changing with time are obtained.

[0061] Step S500, the relationship curve with the highest credibility is extracted from the plurality of relationship curves.

[0062] Step S600, according to the relationship curve with the highest credibility, the response time of the caliper 100 is obtained, for example, the time td corresponding to the 90% rated maximum clamping force on the relationship curve with the highest credibility is obtained, and td is taken as the response time of the caliper 100.

[0063] The test method of the application measures the clamping force of each force sensor under simulated driving conditions to obtain a plurality of relationship curves of the clamping force changing with time, extracts the relationship curve with the highest credibility from the plurality of relationship curves, and obtains the response time of the caliper 100 according to the relationship curve with the highest credibility, so that unreasonable clamping forces measured by each force sensor are eliminated, and the accuracy of the final result is ensured, and the authenticity of the time response test is improved.

[0064] In some embodiments of the application, the test method further comprises step S700: The response time of the caliper 100 tested under various driving conditions is obtained, and the response time is written to the vehicle system. It can be understood that the vehicle system learns the environment in which the vehicle is located through the sensing system of the vehicle, and then learns the response time of the corresponding EMB caliper 100. The sensing system includes a camera, a radar, a temperature sensor, and the like.

[0065] A response threshold is set. If the response time of the caliper 100 is greater than the response threshold, the caliper 100 needs to be braked in advance. For example, the movable end of the caliper 100 is controlled to move a distance, but the pad 110 does not contact the brake disc 210, achieving the effect of pre-braking.

[0066] The present application sets a response threshold, the vehicle system learns the environment in which the vehicle is located through the sensing system of the vehicle, and then learns the response time of the corresponding caliper 100. If the response time of the caliper 100 is greater than the response threshold, it means that the braking of the EMB caliper 100 in this environment is slow, and it is necessary to brake in advance, which significantly improves the driving safety.

[0067] In some embodiments of the present application, the test method, in step S200, sets different environmental conditions of the environment bin 120, and controls the vibration mechanism to generate different jolting amplitudes to simulate various driving conditions, including: The environmental conditions are temperature, rainy day, snowy day, hail, and dust degree, or any combination of temperature, rainy day, snowy day, hail, and dust degree. Each environmental condition needs to be tested for corresponding response time.

[0068] The vibration mechanism is a spring 150. The number and size of the initial pressure applied to the spring 150 are set to obtain different jolting amplitudes. Each setting of the number and size of the initial pressure needs to be tested for corresponding response time.

[0069] By allowing the environmental conditions and the vibration amplitudes to be tested in any combination, and requiring independent testing of the braking response time for each combination, the performance of the EMB assembly under the influence of single factors and composite factors can be evaluated in depth.

[0070] In some embodiments of the present application, the test method, in step S300, the controller 170 controls the caliper 100 to clamp the brake disc 210 with the maximum clamping force under various driving conditions, including: The host computer 180 sends a test preparation instruction to the controller 170, and the controller 170 restores the EMB caliper 100 to the initial position of the motor, i.e., the state of the caliper 100 being released, without applying a braking force to the brake disc 210.

[0071] From t = 0, the controller 170 controls the EMB caliper 100 to clamp the brake disc 210 at the maximum speed specified in the product technical conditions to generate the maximum clamping force specified in the product technical conditions.

[0072] After the host computer 180 collects the maximum clamping force detected by the force sensor, it maintains for 2s, and then controls the caliper 100 to release at the maximum speed specified in the product technical conditions through the controller 170.

[0073] In some embodiments of the present application, the test method, in step S400, a plurality of force sensors synchronously collect the clamping force of the caliper 100 according to the set frequency, and obtain a plurality of relationship curves of the clamping force changing with time according to the clamping force of the caliper 100 changing with time. For example, assuming that there are m force sensors, the m force sensors synchronously collect the clamping force, and the sampling frequency is p times / s. The clamping force collected by one sensor and the time stamp constitute a time sequence of the clamping force, and the time sequence is curve-fitted to obtain a relationship curve of the clamping force changing with time. In this way, the m force sensors can obtain m relationship curves of the clamping force changing with time. Specifically, m is 2, and referring to Figure 7 , the relationship curves of the clamping force changing with time corresponding to the 2 force sensors show that the clamping force first rises rapidly and then gradually stabilizes.

[0074] In some embodiments of the present application, the test method, in step S500, extracts the relationship curve with the highest credibility from the plurality of relationship curves, and referring to Figure 3 , includes: Step S510, taking the intersection point of the plurality of relationship curves as a segmentation point.

[0075] Step S520, obtaining the segmentation point of the plurality of relationship curves according to the slope of the continuous point of the relationship curve.

[0076] Step S530, segmenting the plurality of relationship curves through the segmentation point respectively, so that each relationship curve obtains a plurality of curve segments.

[0077] Step S540, taking the most smooth curve segment as the curve segment with the highest credibility according to the smoothness of the plurality of curve segments in the same period.

[0078] Step S550, obtaining the relationship curve with the highest credibility of the clamping force changing with time by fitting the curve segment with the highest credibility.

[0079] This invention obtains the smoothness of multiple curve segments within the same time period, fits the curve segment with the highest reliability, and obtains the relationship curve with the highest reliability. This allows for the minimum granular filtering out of curve segments with spikes and noise, selecting the high-quality data segments that best reflect the actual braking process for fitting, and finally obtaining a highly reliable relationship curve, thereby significantly improving the accuracy and anti-interference ability of response time calculation.

[0080] In some embodiments of the present invention, in step S520, the test method obtains the segmentation points of multiple relationship curves based on the slope of the continuous points of the relationship curves, and refers to... Figure 4 ,include: Step S521: Set the threshold for the slope change of the relationship curve.

[0081] Step S522: Detect the slope of continuous points of the relationship curve. If the slope difference between two adjacent continuous points of the relationship curve is greater than the slope change threshold, then the point with significant slope change is determined as a segmentation point.

[0082] For example, refer to Figure 7 Select segmentation point t3 on the black curve, segmentation point t2 on the red curve, and then add the intersection point t1 of the two relationship curves, for a total of 3 segmentation points.

[0083] This invention objectively determines segmentation points by setting a slope change threshold, transforming subjective experience-based judgments into quantifiable and consistent algorithmic standards, reducing human error, and improving the automation and repeatability of data analysis.

[0084] In some embodiments of the present invention, in step S530, the testing method divides multiple relationship curves into segments by segmentation points, so that each relationship curve obtains multiple curve segments, as shown in the figure. Figure 5 ,include: Step S531: Based on the segmentation points, obtain the corresponding clamping force time points on the relationship curve, and divide the time period of the relationship curve by the time points.

[0085] Step S532: Based on the time period, obtain the curve segments corresponding to the time period on multiple relationship curves.

[0086] For example, by using the three segmentation points mentioned above to segment both relationship curves, we obtain two curve segments between 0 and t1, two curve segments between t1 and t2, two curve segments between t2 and t3, and two curve segments after t3. The curve segment with the highest reliability can be obtained from each time period.

[0087] The present application obtains time points through segmented points, and obtains time periods through the time points, so as to obtain curve segments on the relational curve, thereby ensuring alignment and fair comparison of multiple curves in the same time dimension, and providing an accurate basis for subsequent smoothness evaluation of the curve segments.

[0088] In some embodiments of the present application, the test method, in step S540, according to the smoothness of the multiple curve segments in the same period, takes the most smooth curve segment as the curve segment with the highest credibility, and refers to Figure 6 , comprising: Step S541, uniformly sampling the multiple curve segments respectively, and obtaining multiple sampling points for the multiple curve segments respectively.

[0089] Step S542, calculating the curvatures of the multiple sampling points for each curve segment respectively, and then calculating the average value of the curvatures of the multiple sampling points.

[0090] Step S543, according to the size of the average value of the curvatures of each curve segment, obtaining the minimum average value of the curvatures.

[0091] The present application quantifies the smoothness of the curve segment by calculating the average value of the curvatures, which is a mathematically rigorous evaluation method, and the smaller the average value of the curvatures is, the smoother the curve segment is, and the higher the credibility is, thereby screening the curve segment with the highest credibility.

[0092] In the description of the present application, the description of the terms "one embodiment, some embodiments, illustrative embodiments, examples, specific examples, or some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0093] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.

Claims

1. A test bench for brake response time of an EMB assembly, characterized in that, include: The caliper is provided with a bushing, the caliper is capable of driving the bushing to move, the bushing is capable of moving close to the brake disc to clamp the brake disc; The environmental chamber is used to provide the environmental simulation conditions required for testing the calipers. A fixing fixture is installed inside the environmental chamber; the fixing fixture is used to install and fix the caliper. A vibration mechanism is used to drive the fixed fixture to vibrate so as to cause the caliper to vibrate. The detection mechanism includes multiple force sensors, which are disposed between the contact area of ​​the caliper and the bushing. When the bushing clamps the brake disc, the force sensors can detect the pressure exerted by the caliper on the bushing.

2. The test bench for brake response time of an EMB assembly according to claim 1, wherein, The environmental chamber is equipped with air conditioning, spraying, and blowing equipment. The air conditioning is used to regulate the temperature of the environmental chamber. The spraying equipment is used to spray water, snow, and ice onto the calipers to simulate rainy, snowy, and hail conditions. The blowing equipment is used to blow sand and dust onto the calipers to simulate dust and gravel conditions during vehicle operation.

3. The test bench for brake response time of an EMB assembly according to claim 1, wherein, The vibration mechanism is a spring. One end of the spring is connected to the fixed fixture, and the other end is connected to the workbench inside the environmental chamber. The spring can drive the caliper to vibrate up and down to simulate different bumpy road conditions during car driving.

4. A test method characterized by, The test method, applied to a test bench for the braking response time of an EMB assembly according to any one of claims 1 to 3, comprises: The caliper is mounted and fixed on the fixture. Different environmental conditions are set in the environmental chamber, and the vibration mechanism is controlled to generate different amplitudes of bumps to simulate various driving conditions. Under various driving conditions, the caliper is controlled to clamp the brake disc with maximum clamping force; Multiple force sensors synchronously acquire the clamping force of the caliper at a set frequency, and obtain multiple relationship curves of the clamping force changing with time based on the clamping force of the caliper changing with time. Extract the relationship curve with the highest reliability from among the multiple relationship curves described; The response time of the caliper is obtained based on the relationship curve with the highest reliability.

5. A test method according to claim 4, wherein, The step of extracting the relationship curve with the highest reliability from multiple relationship curves includes: The intersection points of the multiple relationship curves are used as segmentation points; Based on the slope of the continuous points of the relationship curve, obtain the segmentation points of multiple relationship curves; The multiple relationship curves are segmented by the segmentation points, so that each relationship curve has multiple curve segments; Based on the smoothness of multiple curve segments within the same time period, the smoothest curve segment is selected as the curve segment with the highest reliability. By fitting the curve segment with the highest reliability, the relationship curve with the highest reliability of clamping force changing over time is obtained.

6. A test method according to claim 5, wherein, The step of obtaining the segmentation points of multiple relationship curves based on the slope of continuous points of the relationship curves includes: Set a threshold for the slope change of the relationship curve; The slope of continuous points of the relationship curve is detected. If the slope difference between two adjacent continuous points of the relationship curve is greater than the slope change threshold, the point with a significant slope change is determined as a segmentation point.

7. A test method according to claim 5, wherein, The multiple relationship curves are respectively segmented by the segmentation points, so that each of the relationship curves obtains multiple curve segments, including: According to the segmentation points, time points of corresponding clamping forces on the relationship curves are obtained, and time segments of the relationship curves are segmented by the time points; According to the time segments, curve segments corresponding to the time segments on the multiple relationship curves are obtained.

8. The test method of claim 5, wherein, According to the smoothness of multiple curve segments in the same time segment, the most smooth curve segment is regarded as the curve segment with the highest credibility, including: Multiple sampling points are respectively obtained by uniformly sampling multiple curve segments; The curvature of multiple sampling points is respectively calculated for each curve segment, and then the average value of the curvature of multiple sampling points is obtained; According to the size of the average value of the curvature of each curve segment, the minimum average value of the curvature is obtained.

9. The method of claim 4, wherein, Further comprising: The response time of the caliper tested under various driving conditions is obtained, and the response time is written into the car machine system; A response threshold is set, and if the response time of the caliper is greater than the response threshold, the caliper needs to be braked in advance.

10. The method of claim 4, wherein, The environment conditions of different environment bins are set, and the vibration mechanism is controlled to generate different jolt amplitudes to simulate various driving conditions: The environment conditions are temperature, rainy day, snowy day, hail and dust degree, or any combination of temperature, rainy day, snowy day, hail and dust degree, and corresponding response time tests need to be performed for each environment condition; The vibration mechanism is a spring, and the number and size of initial pressures applied to the spring are set to obtain different jolt amplitudes, and corresponding response time tests need to be performed for each set number and size of initial pressures.

Images