Servo shafting performance test system and method

Abstract

The invention discloses a servo shafting performance test system, which comprises an industrial personal computer, a motion controller, a driver, a direct-current power transformer, a cooling fan group and a tested servo shafting angle measurement element, and is characterized in that the motion controller and the driver form a lower computer to perform bidirectional communication with the industrial personal computer serving as an upper computer; the invention further discloses a testing method, the current, the speed and the angle of the motor in the tested servo shaft system are firstly collected, the friction torque and the eccentric torque of the tested servo shaft system are calculated, finally, the resonant frequency of the tested servo shaft system is calculated, and an analysis result is displayed and stored. The servo shaft system friction torque, eccentric torque and resonance frequency test functions are integrated, the integration level is high, the test repeatability is good, and data are stable.

Description

Technical Field

[0001] The present invention relates to the technical field of servo shaft systems, and in particular to a servo shaft system performance testing system and a testing method thereof. Background Art

[0002] The friction torque, eccentric torque, and resonant frequency characteristics of the servo shaft system are key technical indicators of precision mechanical servo mechanisms. They have a significant impact on the static and dynamic performance of the equipment and determine the response bandwidth and response time of the servo mechanism. In order to improve the overall performance of the equipment servo mechanism, it is necessary to perform dynamic quantitative detection and analysis of the servo shaft system performance.

[0003] In the existing testing technology, the servo shaft friction torque and eccentric torque test technology adopts the spring balance method, that is, the servo shaft to be tested is rotated around its axis by manually pulling the spring balance at a constant speed, reading the spring balance tension value, and measuring the distance from the spring balance tension point to the axis of the shaft system. The dynamic friction torque of the shaft to be tested can be obtained by multiplying the two. Since it is difficult to ensure a constant speed when manually pulling the spring balance during the measurement process, and it is difficult to ensure that the tension direction of the spring balance is always along the tangent direction of the tension point, the measurement accuracy is not high.

[0004] In the existing testing technology, the servo shaft system resonant frequency test technology relies on a commercial modal test system. It is necessary to install multiple sensors in the shaft system to collect the response data of the measuring points, and at the same time, it is necessary to use an excitation device to apply excitation to the measuring points of the shaft system to be tested. This test method is highly mature and can fully obtain the modal frequency, vibration shape, damping and other dynamic characteristics of the shaft system to be tested. However, after the servo shaft system is assembled, there is often no reserved space for installing sensors, which makes the existing testing technology not well applicable to the servo shaft system resonant frequency test.

[0005] Therefore, the existing servo shaft friction torque, eccentric torque, and resonant frequency test systems have low integration, poor test accuracy, and low applicability, which are not convenient for existing tests. Summary of the invention

[0006] In view of the problems existing in the prior art, one of the purposes of the present invention is to provide a servo shaft system performance testing system.

[0007] The technical solution adopted by the present invention to solve its technical problems is: a servo shaft system performance test system, the hardware part includes a shell and a driver installed in the shell and connected to the servo shaft system to be tested and a servo shaft system angle measuring element to be tested, and also includes a motion controller and a DC power transformer installed in the shell and connected to the driver, and an industrial computer outside the shell as a host computer, the DC power transformer is connected to the motion controller and the cooling fan group, the servo shaft system angle measuring element to be tested is connected to the driver, the motion controller and the driver constitute a lower computer and perform two-way communication with the industrial computer as the upper computer, and the industrial computer is used to provide an analysis software running environment and complete data transmission between the lower computer and the industrial computer.

[0008] The servo shaft system performance test system has a shell composed of a bottom plate, four side plates and a top plate connected by screws to form a closed rectangular chassis for providing a base for lower computer installation. A folding handle group and a socket group are respectively provided on the shell.

[0009] The second purpose of the present invention is to provide a servo shaft system performance testing method, in which the upper computer sends a test instruction, and the lower computer drives the servo shaft system under test to move after receiving the test instruction, and collects the servo shaft system motor current, speed, angular position and other information in real time. The collected data is processed, waveform displayed and result stored by the compiled analysis software to obtain the servo shaft system performance parameters, thereby improving the integration of the test instrument and the test accuracy.

[0010] The technical solution adopted by the present invention to solve the technical problem is: a test method for a servo shaft system performance test system, the steps comprising:

[0011] Step 1: Place the servo shaft system to be measured, which is composed of a motor, a load and an angle measuring element, into a housing, and connect the motor and the angle measuring element to the driver and the angle measuring element of the servo shaft system to be measured respectively;

[0012] Step 2: Set the test system parameters through the industrial computer and input the test instructions;

[0013] Step 3: The test system works to collect the current, speed and angle of the motor in the servo axis system under test;

[0014] Step 4: After the test is completed, the collected signal current value is analyzed and processed by the host computer software through the built-in algorithm to calculate the friction torque and eccentricity of the servo shaft system under test;

[0015] Step 5, using the host computer software to perform fast Fourier transform on the collected speed value through the built-in algorithm, and calculate the resonant frequency of the servo shaft system under test;

[0016] Step six: display and store the analysis results.

[0017] Furthermore, the friction torque and eccentric torque in step 4 are calculated by the rotation speed of the servo shaft system under test in the test instruction of step 2.

[0018] Furthermore, the resonant frequency in step 5 is determined by the frequency sweep starting frequency F of the servo axis system under test in the test instruction in step 2. start , Sweep end frequency F end , sweep amplitude A and sweep time T sweep The frequency of the sweep input signal increases linearly, and the calculation formula of the sweep frequency step value β is as follows: β=(F ent -F start ) / T sweep .

[0019] Furthermore, when the servo shaft system under test rotates at a constant speed, the rotation load torque balance equation is K T I=T f1 +T f2 +T p sinγ, where K T is the motor torque coefficient, I is the collected current value, T f1 is the friction torque of the servo mechanism, T f2 is the friction torque of the motor itself, which can be obtained by measuring the corresponding current when the motor rotates at a constant speed without load, γ is the current angular position of the load, T p is the eccentric moment; K T The formula Calculated, where p is the number of poles, N is the total number of conductors in the armature winding, a is the number of parallel branches, and Φ is the total magnetic flux per pole; T p The formula T p =mgR, where m is the mass of the load in the servo shaft system under test, and R is the eccentric radius of the servo shaft system under test.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention collects the speed signal of the servo shaft motor to perform speed loop control, drives the shaft to rotate at a uniform speed, and collects the current signal fed back by the servo shaft motor for calculation and analysis, thereby effectively improving the measurement accuracy.

[0022] 2. The present invention has an output signal interface for absolute angle encoders such as gratings and time gratings, and has dual feedback channels. The compatible resolution range is 18 to 32 bits, and it has strong compatibility and can meet the testing requirements of most precision servo shaft system structures.

[0023] 3. The present invention integrates the servo shaft friction torque, eccentric torque and resonant frequency test functions into one, with high integration, good test repeatability and stable data. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a test system provided by an embodiment of the present invention;

[0025] Figure 2 A top view of the connection of the lower computer of an embodiment of the present invention;

[0026] Figure 3 It is a front view of the connection of the lower computer of an embodiment of the present invention;

[0027] Figure 4 This is a side view of the lower computer connection of an embodiment of the present invention.

[0028] Figure 5 is a principle block diagram of a test system according to an embodiment of the present invention;

[0029] Figure 6 The figure is a flow chart of a testing method according to an embodiment of the present invention.

[0031] The reference numerals of the figures are as follows: 101—industrial computer, 102—motion controller, 103—driver, 104—DC power transformer, 105—cooling fan group, 105a / 105b—cooling fan, 106—angle measuring element of the servo axis system to be measured, 107—servo axis system to be measured, 108—key switch, 109—motor socket, 110—motion controller socket, 111—angle measuring element socket, 112—driver socket, 113—network port, 114—power socket, 115a / 115b—fan net, 201—top plate, 202—left side plate, 203—front side plate, 204—right side plate, 205—rear side plate, 206—bottom plate, 207—folding handle group, 207a / 207b—folding handle. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] The present invention discloses a servo shaft system performance test system based on virtual instruments. The software loaded on the hardware part is analysis software designed based on the Visual Studio software development platform. The software is adapted to the Windows operating system and has a powerful human-computer interaction function. The software is used to complete the configuration of the test hardware, the issuance of test instructions, and the analysis and calculation of test data, waveform display, and result storage.

[0035] The embodiment of the present invention provides a servo shaft system performance test system, the hardware part is as follows Figure 1As shown, it includes an industrial computer 101, a motion controller 102, a driver 103, a DC power transformer 104, a cooling fan group 105, and a servo axis angle measuring element 106. The motion controller 102 and the driver 103 form a lower computer and communicate with the industrial computer 101 as a host computer in a two-way manner. The top view, front view and side view of the lower computer are shown in FIG. Figure 2 , Figure 3 and Figure 4 shown.

[0036] The shell is composed of a bottom plate 206, four side plates (left side plate 202, front side plate 203, right side plate 204, rear side plate 205) and a top plate 201 connected by screws to form a closed rectangular chassis, which is used to provide a base for the lower computer installation. A folding handle group 207 and a socket group are respectively provided on the shell, wherein the folding handle group 207 includes a folding handle 207a and a folding handle 207b, and the socket group includes a motor socket 109, a motion controller socket 110, an angle measuring element socket 111, a driver socket 112, a network port 113 and a power socket 114; the button switch 108 is fixedly installed on the front side plate 203 of the shell.

[0037] The industrial computer 101 as the host computer is used to provide the analysis software running environment, complete the data transmission between the lower computer, complete the parameter configuration of the test system through the host computer, and send the test command to the motion controller 102. The industrial computer 101 and the motion controller 102 communicate with each other in a two-way manner, and send a control command to the motor driver 103 through the motion controller 102 to drive or sweep the servo axis system 107 under test. At the same time, the angle and angular velocity of the servo mechanism are measured through the angle sensor interface, and transmitted to the host computer through the motion controller 102, and the collected signals are processed to obtain the performance characteristics of the object under test. The angle measuring element in the servo axis system 107 under test detects the position information of the load and feeds it back to the motion controller 102 to complete the closed-loop motion control. The present invention realizes the test of indicators such as the friction torque, eccentric torque, and resonant frequency of the servo axis system, and improves the integration and test accuracy of the test instrument.

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following Figure 5 The present invention is further described in detail with reference to embodiments.

[0039] Specifically, the motion controller 102 is installed on the base plate 206; the driver 103 and the folding handle 207a are installed on the left side plate 203; the DC power transformer 104 is installed on the front side plate 203; the cooling fan 105a and the fan net 115a and the cooling fan 105b and the fan net 115b, and the folding handle 207b are installed on the right side plate 204.

[0040] Specifically, the motion controller 102 is connected to the driver 103 via the EntherCAT bus. The motion controller 102 controls 6 axes and has an instruction cycle of 1ms. It is used to receive the test instructions issued by the industrial computer 101, convert them into analog signals and send them to the driver 103. At the same time, it collects the current value and speed value fed back by the motor of the tested servo axis system 107, and the angle position fed back by the angle measuring element 106 of the tested servo axis system, completes the conversion of analog signals to digital signals and uploads them to the industrial computer 101. The industrial computer 101 performs calculations on the test data to obtain the friction torque, eccentric torque and resonant frequency of the servo axis system.

[0041] Specifically, the driver 103 is used to control the speed loop, current loop, and position loop of the motor of the servo axis system 107 under test, and drives the motor of the servo axis system 107 under test to move in a specified pattern according to the instructions sent by the controller according to the received instructions; the driver 103 has an output signal interface for absolute angle encoders such as time gratings and time gratings, and has a dual feedback channel with a compatible resolution range of 18 to 32 bits; the maximum control power of the driver 103 is approximately 1620W (maximum control voltage 90V, maximum control current 20A).

[0042] Specifically, the motion controller 102 is connected to the network port 113 via a network cable, and the industrial computer 101 is connected to the network port 113 via the network cable to achieve two-way communication with the motion controller 102 .

[0043] Specifically, the cooling fan group 105 is installed in the outer casing, including cooling fan No. 1 105a and cooling fan No. 2 105b, which are used for air cooling of the entire chassis; the folding handle group 207 is installed on the outer casing, including folding handle No. 1 207a and folding handle No. 2 207b; the socket group is installed on the outer casing, including 3 DB-9HS sockets, 1 DB-15SL socket, and 1 RJ45 network port, which are used to provide a connection interface between the lower computer and the upper computer.

[0044] Specifically, the DC power transformer 104 is installed in the housing and is used to convert AC load into DC load to power the motion controller 102, the cooling fan group 105, and the driver 103; the DC power transformer 104 adopts 115VAC or 230VAC input and the output DC voltage is 24V.

[0045] Example 2

[0046] Reference Figure 6 As shown, this embodiment provides a servo shaft system performance test system test method based on a virtual instrument, and the specific steps are as follows.

[0047] Step 1: Place the measured servo shaft system 107 composed of a motor, a load and an angle measuring element into a housing, and connect the motor and the angle measuring element to the driver 103 and the measured servo shaft system angle measuring element 106 respectively.

[0048] Step 2: Set the test system parameters through the industrial computer 101 and input the test instructions.

[0049] Step 3: The test system works to collect the current, speed and angle of the motor in the servo axis system 107 under test.

[0050] Step 4, Step 4, after the test is completed, the test data is processed by the torque balance equation and the current value with the help of the host computer software through the built-in algorithm, the collected signal current value is analyzed and processed, and the friction torque and eccentricity of the servo shaft system 107 under test are calculated.

[0051] Specifically, when testing the friction torque and eccentric torque, the input test instruction includes the rotation speed of the servo shaft system 107 to be tested, which is used to control the shaft system to rotate at a constant speed. When testing the resonant frequency, the input test instruction includes the sweep frequency starting frequency F of the servo shaft system 107 to be tested. start , Sweep end frequency F end , sweep amplitude (constant voltage signal) A, sweep time T sweep The frequency of the input signal of the frequency sweep increases in a linear manner. The calculation formula of the step value β of the frequency sweep is as follows: β=(F ent -F start ) / T sweep .

[0052] When the servo shaft system rotates at a constant speed, the rotation load torque balance equation is K T I=T f1 +T f2 +T p sinγ, where K T is the motor torque coefficient; I is the collected current value; T f1 is the friction torque of the servo mechanism; T f2 is the friction torque of the motor itself, which can be obtained by measuring the corresponding current when the motor rotates at a constant speed without load; γ is the current angular position of the load; T p is the eccentric torque.

[0053] Specifically, K T It can be calculated by the following formula: Where p is the number of magnetic poles; N is the total number of conductors in the armature winding; a is the number of parallel branches; Φ is the total magnetic flux per pole.

[0054] Specifically, T p It can be calculated by the following formula: T p=mgR, where m is the mass of the load in the servo shaft system 107 under test; and R is the eccentric radius of the servo shaft system 107 under test.

[0055] Specifically, the analysis and processing of the collected signals include: signal filtering, signal interception, signal sinusoidal function fitting, signal fast Fourier transform (FFT), etc.

[0056] Step 5: Display and store the analysis results. The excitation signal, response signal and calculation results are displayed through the software.

[0057] Specifically, the analysis results are displayed and stored including: excitation signal, response signal, amplitude-frequency curve, phase-frequency curve, resonant frequency, magnification, angle, speed, torque, forward starting torque, reverse starting torque, maximum starting torque, minimum starting torque, friction torque data at different speeds, and eccentric torque test results. Furthermore, the analysis result data can be exported as a .Tdms file for secondary analysis.

[0058] The software of the servo shaft system performance test system provided by the embodiment of the present invention has a software interface such as Figure 3 shown.

[0059] The software interface diagram of the test system of the embodiment of the present invention is, from top to bottom, a schematic diagram of a resonant frequency test interface, a schematic diagram of a starting torque test interface, and a schematic diagram of a motion friction torque and eccentric torque test interface.

[0060] Furthermore, the resonant frequency test interface includes graphical displays of the excitation signal, response signal, amplitude-frequency curve, and phase-frequency curve; the starting torque test interface includes graphical displays of the angle, speed, torque, forward starting torque, and reverse starting torque; the motion friction torque and eccentric torque test interface includes angle, speed, torque, friction torque data at different speeds, and eccentric torque test result displays.

[0061] The servo shaft system performance testing system and method provided by the present invention are introduced above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the scheme of the present invention; at the same time, for general technical personnel in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A servo shaft system performance test system, characterized in that: The invention comprises a housing, a driver (103) and an angle measuring element (106) of the servo shaft system to be measured and installed in the housing, and connected to the driver (107). The invention also comprises a motion controller (102) and a DC power transformer (104) connected to the driver (103), and an industrial computer (101) as a host computer outside the housing. The DC power transformer (104) is connected to the motion controller (102) and a cooling fan group (105). The angle measuring element (106) of the servo shaft system to be measured is connected to the driver (103). The motion controller (102) and the driver (103) communicate with the industrial computer (101) in a bidirectional manner.

2. A servo shaft system performance test system according to claim 1, characterized in that: The shell is formed by a bottom plate, four side plates and a top plate connected by screws, and a folding handle group (207) and a socket group are respectively arranged on the shell.

3. A method for testing a servo shaft system performance test system as claimed in claim 1, characterized in that the steps include: Step 1: placing the servo shaft system (107) to be measured, which is composed of a motor, a load and an angle measuring element, into a housing, and connecting the servo shaft system (107) to be measured with a driver (103) and the angle measuring element (106) to be measured respectively; Step 2, setting the test system parameters and inputting the test instructions through the industrial computer (101); Step 3: Test the system to collect the current, speed and angle of the motor; Step 4, calculating the friction torque and eccentricity of the servo shaft system (107) under test by processing the test data through the torque balance equation and the current value; Step 5, using the host computer software to perform fast Fourier transform on the collected rotation speed value through a built-in algorithm, and calculate the resonant frequency of the servo shaft system (107) under test; Step six: display and store the analysis results.

4. The testing method of a servo shaft system performance testing system according to claim 3, characterized in that: The friction torque and eccentric torque in step 4 are calculated by the rotation speed of the servo shaft system (107) under test in the test instruction of step 2.

5. The testing method of a servo shaft system performance testing system according to claim 4, characterized in that: The resonant frequency in step 5 is determined by the frequency sweep starting frequency F of the servo axis system (107) under test in the test instruction in step 2. start , Sweep end frequency F end , sweep amplitude A and sweep time T sweep The frequency of the sweep input signal increases linearly, and the calculation formula of the sweep frequency step value β is as follows: β=(F ent -F start ) / T sweep .

6. A test method for a servo shaft system performance test system according to claim 3, 4 or 5, characterized in that: When the servo shaft system (107) under test rotates at a constant speed, the rotation load moment balance equation is K T I=T f1 +T f2 +T p ·sinγ, where K T is the motor torque coefficient, I is the collected current value, T f1 is the friction torque of the servo mechanism, T f2 is the friction torque of the motor itself, which is obtained by measuring the corresponding current when the motor rotates at a constant speed without load. γ is the current angular position of the load. T p is the eccentric moment; K T By formula Calculated, where p is the number of pole pairs, N is the total number of conductors in the armature winding, a is the number of parallel branches, and Φ is the total magnetic flux per pole; T p By formula T p = mgR, where m is the mass of the load and R is the eccentric radius of the measured servo shaft system (107).

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