Power assembly vibration exciting force signal detection system and detection method

Abstract

The invention relates to a power assembly vibration exciting force signal detection system which comprises a static signal calibration unit, a dynamic signal acquisition unit and an exciting force signal processing module. The static signal calibration unit comprises a force sensor, a calibration support and a press machine; the static signal calibration unit is used for calibrating the dependent variable of the force sensor in a standard force state; the dynamic signal acquisition unit comprises a force sensor, a suspension support, a suspension cushion and a power assembly; the dynamic signal acquisition unit is used for acquiring a strain signal of the force sensor in the operation process of the engine; and the exciting force signal processing module is used for respectively accessing, acquiring and analyzing an output signal of the static signal calibration unit and an output signal of the dynamic signal acquisition unit. The invention further relates to a power assembly vibration exciting force signal detection method. The force sensor is independently developed, the structure is simple, the cost is low, signals are firm and reliable, the influence of the rigidity of the suspension cushion of the power assembly is avoided, the adaptability is high, and the measurement precision is high.

Description

Technical Field

[0001] The present invention relates to the technical field of engine testing, and in particular to a powertrain vibration excitation force signal detection system and a detection method. Background Art

[0002] During the operation of the engine, periodic cylinder pressure will be generated in the cylinder, and the powertrain suspension installation position will be vibrated by the periodic excitation of the connecting rod, which will cause the powertrain to vibrate axially, horizontally and vertically on the vehicle installation base. If the engine vibration is too large, it will cause greater vibration of the entire vehicle, poor comfort, and even cause vibration damage to its own components. Therefore, it is necessary to detect the engine vibration excitation force during development.

[0003] At present, the vibration acceleration measurement method using an accelerometer is usually used to test the vibration excitation force of the powertrain.

[0004] The defects of the prior art are:

[0005] The stiffness of the powertrain suspension pad has a significant impact on the results of the vibration test, and it is impossible to accurately test the vibration excitation forces of the engine in the axial, horizontal and vertical directions. Summary of the invention

[0006] In view of the above problems, the present invention provides a powertrain vibration excitation force signal detection system and detection method, the purpose of which is to convert the powertrain vibration excitation force into component deformation; it is not affected by the stiffness of the suspension cushion, so that the signal collection is accurate; at the same time, the cost of use is reduced and the test method is convenient and practical.

[0007] To solve the above problems, the technical solution provided by the present invention is:

[0008] The powertrain vibration excitation force signal detection system includes a static signal calibration unit, a dynamic signal acquisition unit and an excitation force signal processing module, wherein:

[0009] The static signal calibration unit comprises a force sensor, a calibration support and a press; the static signal calibration unit is used to calibrate the strain of the force sensor under a standard force state;

[0010] The dynamic signal acquisition unit includes the force sensor, the suspension support, the suspension cushion and the power assembly; the dynamic signal acquisition unit is used to collect the strain signal of the force sensor during the operation of the engine;

[0011] The excitation force signal processing module is used to access, collect and analyze the output signal of the static signal calibration unit and the output signal of the dynamic signal collection unit respectively.

[0012] Preferably, the force sensor is a cylindrical hollow structure; the number of the force sensors is 4;

[0013] The force sensor comprises an upper support column, a lower support column and a circular flange; the upper support column is arranged at the upper half of the force sensor, and a first through hole with a rectangular longitudinal section is opened in the vertical direction of the column; two first support columns with semi-arc outer surfaces are symmetrically arranged on both sides of the first through hole; the lower support column is arranged at the lower half of the force sensor, and a second through hole with a cross-section and four rectangular end faces is opened in the vertical direction of the column; four second support columns with semi-arc outer surfaces are symmetrically arranged around the second through hole; the circular flange is arranged at the upper and lower ends of the force sensor;

[0014] A uniaxial strain gauge is respectively attached to the outer surface of the four second support columns of the lower support column; the attachment direction of the uniaxial strain gauge is parallel to the vertical direction of the second support column; every two uniaxial strain gauges symmetrically along the axis of the lower support column form a half-bridge circuit;

[0015] Two uniaxial strain gauges are respectively attached to the outer surfaces of the two first support columns of the upper support column; the two uniaxial strain gauges are arranged in a T shape.

[0016] Preferably, the calibration support is an L-shaped structure; the support base of the calibration support is installed on the press base; and the side plate of the calibration support is provided with 8 threaded holes for lateral installation of the force sensor.

[0017] Preferably, when the static signal calibration unit calibrates the vertical force, the force sensor on the static signal calibration unit is vertically installed on the press base through a lower support seat; when the static signal calibration unit calibrates the horizontal and axial forces, the force sensor on the static signal calibration unit is laterally installed on the side plate of the calibration support.

[0018] Preferably, the bottom of the force sensor of the dynamic signal acquisition unit is installed on the suspension support, and the suspension pad is installed on the top; the four force sensors are respectively arranged at the four bottom corners of the power assembly to support and install the power assembly.

[0019] Preferably, the suspension support is a rectangular parallelepiped, the bottom is mounted on the test chamber base by bolts, and the force sensor is mounted on the top by bolts; the length, width and height of the suspension support are 200mm*200mm*600mm respectively; the material of the suspension support is Q235, and the number is four;

[0020] The suspension pad is in the shape of a rectangular parallelepiped, with the bottom mounted on the force sensor by bolts, and the top supporting the power assembly by bolts; the length, width and height of the suspension pad are 150mm*80mm*60mm respectively; the stiffness of the suspension pad is 150N / mm axially, 780N / mm horizontally, and 900N / mm vertically; the number of the suspension pads is four.

[0021] The powertrain vibration excitation force signal detection method using the powertrain vibration excitation force signal detection system is characterized by comprising the following steps:

[0022] S100. Apply a standard force to the force sensor of the static signal calibration unit through the press, measure and obtain a static strain signal set of the force sensor under different standard forces in the axial, horizontal and vertical directions, and input the static strain signal set into the excitation force signal processing module;

[0023] S200. The dynamic signal acquisition unit acquires a set of dynamic strain signals in the axial, horizontal and vertical directions measured by the force sensor on the dynamic signal acquisition unit during the operation of the engine, and outputs the set of dynamic strain signals to the excitation force signal processing module;

[0024] S300. After the excitation force signal processing module is respectively connected to the output signals of the static signal calibration unit and the dynamic signal acquisition unit, the collected static strain signal set and the dynamic strain signal set are analyzed and calculated to generate the force signal of the main ignition order of the powertrain.

[0025] Preferably, the step S100 specifically includes the following steps:

[0026] S110. Install the current force sensor and the lower support seat on the press base by bolts; form a full-bridge circuit with two groups of four uniaxial strain gauges arranged in a T shape on the arc-shaped outer surfaces of the two first support columns of the upper support column of the force sensor to output a strain signal in the vertical direction; apply a first standard unit force to the upper bearing seat above the force sensor; output the vertical output strain signal corresponding to the first standard unit force to the excitation force signal processing module;

[0027] The first standard unit force is expressed as follows:

[0028] F1=300n1

[0029] Wherein, F1 is used to represent the first standard unit force; n1 is used to represent the first multiplier of the first standard unit force, n1=0, 1...10;

[0030] The vertical output strain signal is expressed as follows:

[0031]

[0032] Among them, M V (F1) used to characterize the vertical output strain signal corresponding to the first standard unit force; used to characterize each of the first standard unit forces corresponding to each of the first multipliers; used to characterize each of the vertical direction output strain signals corresponding to each of the first standard unit forces;

[0033] S120. Install the calibration support on the press base; install the force sensor laterally on the calibration support through the bolt connection of the lower support seat; form a half-bridge circuit with the first uniaxial strain gauge and the third uniaxial strain gauge on the lower support column of the force sensor to output a strain signal in the axial direction; apply a second standard unit force to the side of the upper bearing seat above the force sensor; output the axial direction output strain signal corresponding to the second standard unit force to the excitation force signal processing module;

[0034] The second standard unit force is expressed as follows:

[0035] F2=50n2

[0036] Wherein, F2 is used to represent the second standard unit force; n2 is used to represent the second multiplier of the second standard unit force, n2=0, 1...10;

[0037] The axial output strain signal is expressed as follows:

[0038]

[0039] Among them, M A (F2) used to characterize the axial output strain signal corresponding to the second standard unit force; used to characterize each of the second standard unit forces corresponding to each of the second multipliers; used to characterize each of the axial direction output strain signals corresponding to each of the second standard unit forces;

[0040] S130. Rotate the lower support seat of the force sensor clockwise by 90°, and install it laterally on the calibration support again by bolts; form a half-bridge circuit with the second uniaxial strain gauge and the fourth uniaxial strain gauge on the lower support column of the force sensor to output a strain signal in the horizontal direction; apply a third standard unit force to the side of the upper bearing seat above the force sensor; output the horizontal output strain signal corresponding to the third standard unit force to the excitation force signal processing module;

[0041] The third standard unit force is expressed as follows:

[0042] F3=50n3

[0043] Wherein, F3 is used to represent the third standard unit force; n3 is used to represent the third multiplier of the third standard unit force, n3=0, 1...10;

[0044] The horizontal output strain signal is expressed as follows:

[0045]

[0046] Among them, M H (F3) used to characterize the horizontal output strain signal corresponding to the third standard unit force; used to characterize each of the third standard unit forces corresponding to each of the third multipliers; used to characterize each of the horizontal direction output strain signals corresponding to each of the third standard unit forces;

[0047] S140. Switch to the next force sensor, and then execute steps S110 to S130 until the static calibration of the four force sensors of the static signal calibration unit in the vertical, axial and horizontal directions is completed.

[0048] Preferably, the step S200 specifically includes the following steps:

[0049] S210. Install the lower support seats of the four force sensors on the suspension support of the engine pedestal; install the suspension cushion on the upper force bearing seat of the force sensor; install the powertrain on the suspension cushion; output the axial, horizontal and vertical strain signals of the four groups of force sensors to the excitation force signal processing module;

[0050] S220. Start the engine and collect the dynamic strain signal set; the dynamic strain signal set includes 12 strain signals in the axial, horizontal and vertical directions of the four force sensors; after the dynamic strain signal set is collected, it is input into the excitation force signal processing module;

[0051] The dynamic strain signal set is expressed as follows:

[0052]

[0053] Wherein: M(t) is used to characterize the dynamic strain signal set; t is used to characterize the time parameter, the unit is second, and 20s≤t≤50s, and the system sampling rate is 1024Hz; An axial strain signal for characterizing the i-th force sensor; A strain signal for representing the horizontal direction of the i-th force sensor; Used to characterize the strain signal in the vertical direction of the ith force sensor.

[0054] Preferably, the step S300 specifically includes the following steps:

[0055] S310: Perform point fitting on the static strain signal set input by the static signal calibration unit to generate a linear curve; the linear curve is expressed as follows:

[0056] F=K(M)+b

[0057] Wherein: F is used to characterize the linear curve; M is used to characterize the strain of each force sensor under a set of standard forces; K is used to characterize the fitting coefficient of each channel of the force sensor; b is used to characterize the fitting constant of each channel of the force sensor;

[0058] S320: Performing a fast Fourier transform point by point on the dynamic strain signal set input by the dynamic signal acquisition unit into a frequency domain signal, which is expressed as follows:

[0059]

[0060] Where: M k Used to represent the Fourier coefficient set; L is used to represent the signal M k The number of; m is used to represent the Fourier analysis frequency set, Δf is used to characterize the frequency resolution and is set to 1 Hz.

[0061] S330: Calculate the order frequency of the main ignition excitation force of the engine, expressed as follows:

[0062] O i =n×c×i / 120,i=1,2,3,4

[0063] Among them: n is used to represent the engine speed, the unit is revolutions per minute; c is used to represent the number of cylinders in a four-stroke engine; i is used to represent the main ignition order;

[0064] S340: extracting the strain signal of the main firing order in the frequency domain signal;

[0065] S350: Calculate the excitation force signal of the main ignition order of the output powertrain, expressed as follows:

[0066]

[0067] Wherein: k1, k2, k3, k4 are respectively used to characterize the fitting coefficients of the four force sensors, and the superscripts A, H and V represent the axial, horizontal and vertical directions respectively; b1, b2, b3, b4 are respectively used to characterize the fitting constants of the four force sensors, and the superscripts A, H and V represent the axial, horizontal and vertical directions respectively; Z1, Z2, Z3, Z4 are respectively used to characterize the Fourier transform data of the strain signals collected by the four force sensors, and the superscripts A, H and V represent the axial, horizontal and vertical directions respectively;

[0068] Then the vibration excitation force signal at the main firing order frequency of the powertrain is generated.

[0069] Compared with the prior art, the present invention has the following advantages:

[0070] 1. The present invention cleverly uses the principle of vibration force-component deformation, thereby converting the powertrain vibration excitation force into component deformation.

[0071] 2. Since the present invention simultaneously restores the deformation of the component into the excitation force through the standard press, the vibration excitation force signal of the powertrain is directly tested and measured, which is not affected by the stiffness of the suspension cushion and the signal is accurately collected.

[0072] 3. The device of the present invention has an ingenious structure, low cost, and a firm and reliable signal. The method for calculating and analyzing the vibration excitation force of the powertrain is ingeniously conceived, practical, and convenient. It solves technical problems in the industry and is easy to promote and use in the field of powertrain testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is a structural schematic diagram of a powertrain vibration excitation force signal detection system according to a specific embodiment of the present invention;

[0074] Figure 2 A schematic diagram of a force sensor according to a specific embodiment of the present invention;

[0075] Figure 3 It is a schematic diagram of static calibration in the vertical direction of a specific embodiment of the present invention;

[0076] Figure 4 It is a schematic diagram of the arrangement of the horizontal force sensor according to a specific embodiment of the present invention;

[0077] Figure 5It is a schematic diagram of the force-strain fitting curve of the axial channel of the force sensor of a specific embodiment of the present invention;

[0078] Figure 6 It is a schematic diagram of the axial vibration excitation force of the main firing frequency orders of the force sensor of a specific embodiment of the present invention;

[0079] Figure 7 It is a schematic diagram of the dynamic signal acquisition structure of a specific embodiment of the present invention.

[0080] Wherein: 100. force sensor, 200. calibration support, 110. upper support column, 120. lower support column, 130. circular flange, 111. first through hole, 112. first support column, 121. second through hole, 122. second support column, 123. uniaxial strain gauge, 210. support base, 220. side plate, 310. press base, 320. press rod, 410. lower support seat, 420. upper bearing seat, R1. first uniaxial strain gauge, R2. second uniaxial strain gauge, R3. third uniaxial strain gauge, R4. fourth uniaxial strain gauge, R5. fifth uniaxial strain gauge, R6. sixth uniaxial strain gauge, R7. seventh uniaxial strain gauge, R8. eighth uniaxial strain gauge DETAILED DESCRIPTION

[0081] The present invention is further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0082] like Figure 1 As shown, the powertrain vibration excitation force signal detection system includes a static signal calibration unit, a dynamic signal acquisition unit and an excitation force signal processing module, wherein:

[0083] The static signal calibration unit comprises a force sensor 100, a calibration support 200 and a press; the static signal calibration unit is used to calibrate the strain amount of the force sensor 100 under a standard force state.

[0084] The dynamic signal acquisition unit includes a force sensor 100, a suspension support, a suspension cushion and a power assembly; the dynamic signal acquisition unit is used to collect the strain signal of the force sensor 100 during the operation of the engine.

[0085] The excitation force signal processing module is used to access, collect and analyze the output signal of the static signal calibration unit and the output signal of the dynamic signal acquisition unit respectively.

[0086] It should be noted that the static signal calibration unit is used to calibrate the strain of the force sensor 100 under the standard force state, and obtain the relationship between the force and strain of the force sensor 100 in the axial, horizontal and vertical directions; the signal output by the static signal calibration unit is input into the excitation force signal processing module.

[0087] It should be noted that the dynamic signal acquisition unit is used to collect the strain signal of the force sensor 100 during the operation of the engine, and obtain the relationship between the strain signal and time of the force sensor 100 in the axial, horizontal and vertical directions in this state, which is expressed as formula 1:

[0088] Y(t)={(t0,με0),(t1,με1),......(t n ,με n )} (1)

[0089] Among them: με is used to characterize microstrain; με n Used to characterize the microstrain at the nth moment.

[0090] The signal output by the dynamic signal acquisition unit is input into the excitation force signal processing module.

[0091] It should be noted that the excitation force signal processing module analyzes and calculates the collected strain signals to generate the force signals of the main ignition order of the powertrain, which can be expressed as follows:

[0092] F(i)={(o1,f0),(o2,f1),......(o6,f n )} (2)

[0093] Where i=1,2,3,4,5,6.

[0094] like Figure 2 As shown, it should be noted that the force sensor 100 is a cylindrical hollow structure; the number of the force sensors 100 is 4.

[0095] The force sensor 100 includes an upper support column 110, a lower support column 120 and a circular flange 130; the upper support column 110 is arranged in the upper half of the force sensor 100, and a first through hole 111 with a rectangular longitudinal section is opened in the vertical direction of the column; two first support columns 112 with semi-arc outer surfaces are symmetrically arranged on both sides of the first through hole 111; the lower support column 120 is arranged in the lower half of the force sensor 100, and a second through hole 121 with a cross-section and four rectangular end faces of the cross is opened in the vertical direction of the column; four second support columns 122 with semi-arc outer surfaces are symmetrically arranged around the second through hole 121; the circular flange 130 is arranged at the upper and lower ends of the force sensor 100.

[0096] A uniaxial strain gauge 123 is respectively pasted on the outer surface of the four second support columns 122 of the lower support column 120; the pasting direction of the uniaxial strain gauge 123 is parallel to the vertical direction of the second support column 122; every two uniaxial strain gauges 123 symmetrical along the axis of the lower support column 120 form a half-bridge circuit for testing axial and horizontal forces.

[0097] Two T-shaped uniaxial strain gauges 123 are respectively attached to the outer surfaces of the two first support columns 112 of the upper support column 110. A total of four uniaxial strain gauges 123 form a full-bridge circuit for testing the vertical force.

[0098] It should be further explained that the circular flange 130 is used for fixed installation and is made of Q235.

[0099] It should be noted that the calibration support 200 is an L-shaped structure; the support base 210 of the calibration support 200 is installed on the press base 310; and the side plate 220 of the calibration support 200 has 8 threaded holes for lateral installation of the force sensor 100.

[0100] It should be further explained that the calibration support 200 is used to calibrate the forces in the axial and horizontal directions of the force sensor, and the material is Q235.

[0101] In this specific embodiment, the model of the press is Zwick Z300E, with a maximum pressure of 30KN and an accuracy of 1N.

[0102] like Figure 3 , Figure 4 As shown, it should be noted that when the static signal calibration unit calibrates the vertical force, the force sensor 100 on the static signal calibration unit is vertically installed on the press base 310 through the lower support seat 410; when the static signal calibration unit calibrates the horizontal and axial forces, the force sensor 100 on the static signal calibration unit is laterally installed on the side plate 220 of the calibration support 200.

[0103] In this specific embodiment, the system sampling rate of the static signal calibration unit is 64 Hz, and the system sampling time interval is 20 seconds to 50 seconds.

[0104] It should be noted that the bottom of the force sensor 100 of the dynamic signal acquisition unit is installed on the suspension support, and a suspension cushion is installed on the top; four force sensors 100 are respectively arranged at the four bottom corners of the powertrain to support the installation of the powertrain. When the powertrain is running, the force sensor 100 outputs 4 sets of axial, horizontal and vertical strain signals, a total of 12 signals, which are input into the excitation force signal processing module.

[0105] In this specific embodiment, the system sampling rate of the dynamic signal acquisition unit is 1024 Hz, and the system sampling time interval is 20 seconds to 50 seconds.

[0106] It should be noted that the suspension support is a rectangular parallelepiped, the bottom is mounted on the test chamber base by bolts, and the force sensor 100 is mounted on the top by bolts; the length, width and height of the suspension support are 200mm*200mm*600mm respectively; the material of the suspension support is Q235, and the number is four.

[0107] The suspension pad is in the shape of a cuboid, with the bottom mounted on the force sensor 100 by bolts, and the top supporting the power assembly by bolts; the length, width and height of the suspension pad are 150mm*80mm*60mm respectively; the stiffness of the suspension pad is 150N / mm axially, 780N / mm horizontally, and 900N / mm vertically; there are four suspension pads.

[0108] A powertrain vibration excitation force signal detection method using a powertrain vibration excitation force signal detection system comprises the following steps:

[0109] S100. Apply a standard force to the force sensor 100 of the static signal calibration unit through a press, measure the static strain signal set of the force sensor 100 under different standard forces in the axial, horizontal and vertical directions, and input the static strain signal set into the excitation force signal processing module.

[0110] S200. The dynamic signal acquisition unit acquires a set of dynamic strain signals in the axial, horizontal and vertical directions measured by the force sensor 100 on the dynamic signal acquisition unit during the operation of the engine, and outputs the set of dynamic strain signals to the excitation force signal processing module.

[0111] S300. After the excitation force signal processing module is connected to the output signals of the static signal calibration unit and the dynamic signal acquisition unit respectively, the collected static strain signal set and dynamic strain signal set are analyzed and calculated to generate the force signal of the main ignition order of the powertrain.

[0112] It should be noted that step S100 specifically includes the following steps:

[0113] S110. Install the current force sensor 100 and the lower support seat 410 on the press base 310 by bolts; form a full-bridge circuit with two groups of four uniaxial strain gauges 123 arranged in a T shape on the arc-shaped outer surfaces of the two first support columns 112 of the upper support column 110 of the force sensor 100 to output a strain signal in the vertical direction; the press rod 320 applies a first standard unit force on the upper force bearing seat 420 above the force sensor 100; output the vertical output strain signal corresponding to the first standard unit force to the excitation force signal processing module.

[0114] The first standard unit force is expressed as follows:

[0115] F1=300n1 (3)

[0116] Among them, F1 is used to represent the first standard unit force; n1 is used to represent the first multiplier of the first standard unit force, n1=0, 1...10.

[0117] The vertical output strain signal is expressed as follows:

[0118]

[0119] Among them, M V (F1) is used to characterize the vertical output strain signal corresponding to the first standard unit force; Used to characterize each first standard unit force corresponding to each first multiplier; Used to characterize each vertical output strain signal corresponding to each first standard unit force.

[0120] S120. Install the calibration support 200 on the press base 310; install the force sensor 100 laterally on the calibration support 200 through the bolt connection of the lower support seat 410; form a half-bridge circuit with the first uniaxial strain gauge R1 and the third uniaxial strain gauge R3 on the lower support column 120 of the force sensor 100 to output the strain signal in the axial direction; apply a second standard unit force to the side of the upper bearing seat 420 above the force sensor 100; output the axial direction output strain signal corresponding to the second standard unit force to the excitation force signal processing module.

[0121] The second standard unit force is expressed by formula 5:

[0122] F2=50n2 (5)

[0123] Among them, F2 is used to represent the second standard unit force; n2 is used to represent the second multiplier of the second standard unit force, n2=0, 1...10.

[0124] The output strain signal in the axial direction is expressed as follows:

[0125]

[0126] Among them, M A (F2) is used to characterize the axial output strain signal corresponding to the second standard unit force; Used to characterize each second standard unit force corresponding to each second multiplier; Used to characterize the output strain signal in each axial direction corresponding to each second standard unit force.

[0127] S130. Rotate the lower support seat 410 of the force sensor 100 clockwise by 90°, and install it laterally on the calibration support 200 again by bolts; the second uniaxial strain gauge R2 and the fourth uniaxial strain gauge R4 on the lower support column 120 of the force sensor 100 form a half-bridge circuit to output a strain signal in the horizontal direction; apply a third standard unit force to the side of the upper bearing seat 420 above the force sensor 100; output the horizontal output strain signal corresponding to the third standard unit force to the excitation force signal processing module.

[0128] The third standard unit force is expressed by formula 7:

[0129] F3=50n3 (7)

[0130] Among them, F3 is used to represent the third standard unit force; n3 is used to represent the third multiplier of the third standard unit force, n3=0, 1...10.

[0131] The horizontal output strain signal is expressed as follows:

[0132]

[0133] Among them, M H (F3) is used to characterize the horizontal output strain signal corresponding to the third standard unit force; Used to characterize each third standard unit force corresponding to each third multiplier; Used to characterize each horizontal output strain signal corresponding to each third standard unit force.

[0134] S140. Switch to the next force sensor 100, and then execute steps S110 to S130 until the static calibration of the four force sensors 100 of the static signal calibration unit in the vertical, axial and horizontal directions is completed.

[0135] It should be further explained that in step S110, a uniaxial strain gauge is pasted on the lower support column 120 of the force sensor 100, and the strain grid direction is along the axial direction of the force sensor 100. One strain gauge is pasted on each support column, totaling 4 strain gauges, which are marked as the first uniaxial strain gauge R1, the second uniaxial strain gauge R2, the third uniaxial strain gauge R3 and the fourth uniaxial strain gauge R4; two strain gauges are pasted on the upper support column 110 of the force sensor, two strain gauges are on each support column, totaling 4 strain gauges, which are marked as the fifth uniaxial strain gauge R5, the sixth uniaxial strain gauge R6, the seventh uniaxial strain gauge R7 and the eighth uniaxial strain gauge R8, wherein the strain grid directions of the fifth uniaxial strain gauge R5 and the seventh uniaxial strain gauge R7 are along the axial direction of the force sensor, and the strain grid directions of the sixth uniaxial strain gauge R6 and the eighth uniaxial strain gauge R8 are along the arc direction of the support column, and are respectively perpendicular to the seventh uniaxial strain gauge R7 and the fifth uniaxial strain gauge R5.

[0136] It should be noted that step S200 specifically includes the following steps:

[0137] S210. Install the lower support base 410 of the four force sensors 100 on the suspension support of the engine stand; install the suspension pad on the upper force bearing base 420 of the force sensor 100; install the powertrain on the suspension pad; output the axial, horizontal and vertical strain signals of the four groups of force sensors 100 to the excitation force signal processing module.

[0138] S220. Start the engine and collect a dynamic strain signal set; the dynamic strain signal set includes a total of 12 strain signals in the axial, horizontal and vertical directions of the four force sensors 100; after the dynamic strain signal set is collected, it is input into the excitation force signal processing module.

[0139] The dynamic strain signal set is expressed as follows:

[0140]

[0141] Where: M(t) is used to characterize the dynamic strain signal set; t is used to characterize the time parameter, the unit is second, and 20s≤t≤50s, the system sampling rate is 1024Hz; An axial strain signal for characterizing the i-th force sensor 100; A strain signal for representing the horizontal direction of the i-th force sensor 100; Used to represent the strain signal of the i-th force sensor 100 in the vertical direction.

[0142] It should be noted that step S300 specifically includes the following steps:

[0143] S310: Perform point fitting on the static strain signal set input by the static signal calibration unit to generate a linear curve; the linear curve is expressed as follows:

[0144] F=K(M)+b (10)

[0145] Among them: F is used to characterize the linear curve; M is used to characterize the strain of each force sensor 100 under a set of standard forces; K is used to characterize the fitting coefficient of each channel of the force sensor 100; b is used to characterize the fitting constant of each channel of the force sensor 100.

[0146] S320: Performing a fast Fourier transform point by point on the dynamic strain signal set input by the dynamic signal acquisition unit into a frequency domain signal, which is expressed as follows:

[0147]

[0148] Where: M kUsed to represent the Fourier coefficient set; L is used to represent the signal M k The number of; m is used to represent the Fourier analysis frequency set, Δf is used to characterize the frequency resolution and is set to 1 Hz.

[0149] S330: Calculate the order frequency of the main ignition excitation force of the engine, expressed as formula 12:

[0150] O i =n×c×i / 120,i=1,2,3,4 (12)

[0151] Among them: n is used to represent the engine speed, the unit is revolutions per minute; c is used to represent the number of cylinders in a four-stroke engine; i is used to represent the main ignition order.

[0152] S340: extracting strain signals of main firing orders in the frequency domain signal.

[0153] S350: Calculate the excitation force signal of the main ignition order of the output powertrain, expressed as formula 13:

[0154]

[0155] Among them: k1, k2, k3, k4 are respectively used to characterize the fitting coefficients of the four force sensors 100, and the superscripts A, H and V represent the axial, horizontal and vertical directions respectively; b1, b2, b3, b4 are respectively used to characterize the fitting constants of the four force sensors 100, and the superscripts A, H and V represent the axial, horizontal and vertical directions respectively; Z1, Z2, Z3, Z4 are respectively used to characterize the Fourier transform data of the strain signals collected by the four force sensors 100, and the superscripts A, H and V represent the axial, horizontal and vertical directions respectively.

[0156] Then the vibration excitation force signal at the main firing order frequency of the powertrain is generated.

[0157] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0158] The disclosed embodiments are described above to enable any person skilled in the art to implement or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined herein may also be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0159] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0160] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A powertrain vibration excitation force signal detection system, characterized in that: It includes a static signal calibration unit, a dynamic signal acquisition unit and an excitation force signal processing module, wherein: The static signal calibration unit comprises a force sensor (100), a calibration support (200) and a press; the static signal calibration unit is used to calibrate the strain amount of the force sensor (100) under a standard force state; The dynamic signal acquisition unit comprises the force sensor (100), a suspension support, a suspension cushion and a power assembly; the dynamic signal acquisition unit is used to collect the strain signal of the force sensor (100) during the operation of the engine; The excitation force signal processing module is used to access, collect and analyze the output signal of the static signal calibration unit and the output signal of the dynamic signal collection unit respectively.

2. The powertrain vibration excitation force signal detection system according to claim 1, characterized in that: The force sensor (100) is a cylindrical hollow structure; the number of the force sensors (100) is four; The force sensor (100) comprises an upper support column (110), a lower support column (120) and a circular flange (130); the upper support column (110) is arranged at the upper half of the force sensor (100), and a first through hole (111) with a rectangular longitudinal section is opened in the vertical direction of the column; two first support columns (112) with semi-arc outer surfaces are symmetrically arranged on both sides of the first through hole (111); the lower support column (120) is arranged at the lower half of the force sensor (100), and a second through hole (121) with a cross-section and four rectangular end faces of the cross is opened in the vertical direction of the column; four second support columns (122) with semi-arc outer surfaces are symmetrically arranged around the second through hole (121); the circular flange (130) is arranged at the upper and lower ends of the force sensor (100); A uniaxial strain gauge (123) is respectively attached to the outer surface of the four second support columns (122) of the lower support column (120); the attachment direction of the uniaxial strain gauge (123) is parallel to the vertical direction of the second support column (122); and every two uniaxial strain gauges (123) symmetrically arranged along the axis of the lower support column (120) form a half-bridge circuit; Two uniaxial strain gauges (123) are respectively adhered to the outer surfaces of the two first support columns (112) of the upper support column (110); the two uniaxial strain gauges (123) are arranged in a T shape.

3. The powertrain vibration excitation force signal detection system according to claim 2, characterized in that: The calibration support (200) is an L-shaped structure; the support base (210) of the calibration support (200) is installed on the press base (310); and the side plate (220) of the calibration support (200) is provided with 8 threaded holes for laterally installing the force sensor (100).

4. The powertrain vibration excitation force signal detection system according to claim 3, characterized in that: When the static signal calibration unit calibrates vertical force, the force sensor (100) on the static signal calibration unit is vertically mounted on the press base (310) via a lower support seat (410); when the static signal calibration unit calibrates horizontal and axial forces, the force sensor (100) on the static signal calibration unit is laterally mounted on the side plate (220) of the calibration support (200).

5. The powertrain vibration excitation force signal detection system according to claim 4, characterized in that: The bottom of the force sensor (100) of the dynamic signal acquisition unit is installed on the suspension support, and the suspension cushion is installed on the top; four force sensors (100) are respectively arranged at the four bottom corners of the power assembly to support and install the power assembly.

6. The powertrain vibration excitation force signal detection system according to claim 5, characterized in that: The suspension support is a rectangular parallelepiped, the bottom of which is mounted on the test chamber base by bolts, and the upper part of which is mounted with the force sensor (100) by bolts; the length, width and height of the suspension support are 200 mm*200 mm*600 mm respectively; the material of the suspension support is Q235, and the number is four; The suspension pad is in the shape of a rectangular parallelepiped, the bottom of which is mounted on the force sensor (100) by bolts, and the top of which supports the power assembly by bolts; the length, width and height of the suspension pad are 150 mm*80 mm*60 mm respectively; the stiffness of the suspension pad is 150 N / mm in the axial direction, 780 N / mm in the horizontal direction and 900 N / mm in the vertical direction; and the number of the suspension pads is four.

7. A method for detecting a powertrain vibration excitation force signal using the powertrain vibration excitation force signal detection system according to claim 6, characterized in that: The following steps are involved: S100. Applying a standard force to the force sensor (100) of the static signal calibration unit through the press, measuring and obtaining a static strain signal set of the force sensor (100) under different standard forces in the axial, horizontal and vertical directions, and inputting the static strain signal set into the excitation force signal processing module; S200. The dynamic signal acquisition unit acquires a set of dynamic strain signals in the axial, horizontal and vertical directions measured by the force sensor (100) on the dynamic signal acquisition unit during the operation of the engine, and outputs the set of dynamic strain signals to the excitation force signal processing module; S300. After the excitation force signal processing module is respectively connected to the output signals of the static signal calibration unit and the dynamic signal acquisition unit, the collected static strain signal set and the dynamic strain signal set are analyzed and calculated to generate the force signal of the main ignition order of the powertrain.

8. The method for detecting a powertrain vibration excitation force signal according to claim 7, characterized in that: The step S100 specifically includes the following steps: S110. The current force sensor (100) and the lower support seat (410) are mounted on the press base (310) by means of bolts; two groups of four uniaxial strain gauges (123) arranged in a T-shape on the arc-shaped outer surfaces of the two first support columns (112) of the upper support column (110) of the force sensor (100) are used to form a full-bridge circuit to output a strain signal in the vertical direction; a first standard unit force is applied to the upper bearing seat (420) above the force sensor (100); Outputting the vertical direction output strain signal corresponding to the first standard unit force to the excitation force signal processing module; The first standard unit force is expressed as follows: F1=300n1 Wherein, F1 is used to represent the first standard unit force; n1 is used to represent the first multiplier of the first standard unit force, n1=0, 1...10; The vertical output strain signal is expressed as follows: Among them, M V (F1) used to characterize the vertical output strain signal corresponding to the first standard unit force; used to characterize each of the first standard unit forces corresponding to each of the first multipliers; used to characterize each of the vertical direction output strain signals corresponding to each of the first standard unit forces; S120. Install the calibration support (200) on the press base (310); install the force sensor (100) laterally on the calibration support (200) through the bolt connection of the lower support seat (410); form a half-bridge circuit with the first uniaxial strain gauge (R1) and the third uniaxial strain gauge (R3) on the lower support column (120) of the force sensor (100) to output a strain signal in the axial direction; apply a second standard unit force to the side of the upper bearing seat (420) above the force sensor (100); output the axial direction output strain signal corresponding to the second standard unit force to the excitation force signal processing module; The second standard unit force is expressed as follows: F2=50n2 Wherein, F2 is used to represent the second standard unit force; n2 is used to represent the second multiplier of the second standard unit force, n2=0, 1...10; The axial output strain signal is expressed as follows: Among them, M A (F2) used to characterize the axial output strain signal corresponding to the second standard unit force; used to characterize each of the second standard unit forces corresponding to each of the second multipliers; used to characterize each of the axial direction output strain signals corresponding to each of the second standard unit forces; S130. The lower support seat (410) of the force sensor (100) is rotated 90° clockwise and installed laterally on the calibration support (200) again by bolts; the second uniaxial strain gauge (R2) and the fourth uniaxial strain gauge (R4) on the lower support column (120) of the force sensor (100) form a half-bridge circuit to output a strain signal in the horizontal direction; a third standard unit force is applied to the side of the upper bearing seat (420) above the force sensor (100); and the horizontal output strain signal corresponding to the third standard unit force is output to the excitation force signal processing module; The third standard unit force is expressed as follows: F3=50n3 Wherein, F3 is used to represent the third standard unit force; n3 is used to represent the third multiplier of the third standard unit force, n3=0, 1...10; The horizontal output strain signal is expressed as follows: Among them, M H (F30 is used to characterize the horizontal output strain signal corresponding to the third standard unit force; used to characterize each of the third standard unit forces corresponding to each of the third multipliers; used to characterize each of the horizontal direction output strain signals corresponding to each of the third standard unit forces; S140. Switch to the next force sensor (100), and then execute steps S110 to S130 until the static calibration of the four force sensors (100) of the static signal calibration unit in the vertical, axial and horizontal directions is completed.

9. The method for detecting a powertrain vibration excitation force signal according to claim 8, characterized in that: The step S200 specifically includes the following steps: S210. Install the lower support seats (410) of the four force sensors (100) on the suspension support of the engine stand; install the suspension cushion on the upper force bearing seat (420) of the force sensor (100); install the powertrain on the suspension cushion; output the axial, horizontal and vertical strain signals of the four groups of force sensors (100) to the excitation force signal processing module; S220. Start the engine and collect the dynamic strain signal set; the dynamic strain signal set includes a total of 12 strain signals in the axial, horizontal and vertical directions of the four force sensors (100); after the dynamic strain signal set is collected, it is input into the excitation force signal processing module; The dynamic strain signal set is expressed as follows: Wherein: M(t) is used to characterize the dynamic strain signal set; t is used to characterize the time parameter, the unit is second, and 20s≤t≤50s, and the system sampling rate is 1024Hz; A signal for characterizing an axial strain of the i-th force sensor (100); A strain signal for characterizing the horizontal direction of the i-th force sensor (100); Used to characterize the strain signal in the vertical direction of the i-th force sensor (100).

10. The method for detecting a powertrain vibration excitation force signal according to claim 9, characterized in that: The step S300 specifically includes the following steps: S310: Perform point fitting on the static strain signal set input by the static signal calibration unit to generate a linear curve; the linear curve is expressed as follows: F=K(M)+b Wherein: F is used to characterize the linear curve; M is used to characterize the strain of each force sensor (100) under a set of standard forces; K is used to characterize the fitting coefficient of each channel of the force sensor (100); and b is used to characterize the fitting constant of each channel of the force sensor (100); S320: Performing a fast Fourier transform point by point on the dynamic strain signal set input by the dynamic signal acquisition unit into a frequency domain signal, which is expressed as follows: Where: M k Used to represent the Fourier coefficient set; L is used to represent the signal M k The number of; m is used to represent the Fourier analysis frequency set, Δf is used to characterize the frequency resolution and is set to 1 Hz. S330: Calculate the order frequency of the main ignition excitation force of the engine, expressed as follows: The i =n×c×i / 120,i=1,2,3,4 Among them: n is used to represent the engine speed, the unit is revolutions per minute; c is used to represent the number of cylinders in a four-stroke engine; i is used to represent the main ignition order; S340: extracting the strain signal of the main firing order in the frequency domain signal; S350: Calculate the excitation force signal of the main ignition order of the output powertrain, expressed as follows: Wherein: k1, k2, k3, k4 are respectively used to characterize the fitting coefficients of the four force sensors (100), and the superscripts A, H and V respectively represent the axial, horizontal and vertical directions; b1, b2, b3, b4 are respectively used to characterize the fitting constants of the four force sensors (100), and the superscripts A, H and V respectively represent the axial, horizontal and vertical directions; Z1, Z2, Z3, Z4 are respectively used to characterize the Fourier transform data of the strain signals collected by the four force sensors (100), and the superscripts A, H and V respectively represent the axial, horizontal and vertical directions; Then the vibration excitation force signal at the main firing order frequency of the powertrain is generated.

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