Vertical and horizontal pentahedron machining center lead screw test bench with automatic temperature compensation function

Abstract

The invention relates to a vertical and horizontal pentahedron machining center ball screw test bench with automatic temperature compensation, which comprises a base, a workbench and a numerical control table, and is characterized in that the workbench comprises a transverse workbench, a longitudinal workbench and a stand column, and the workbench is internally provided with a screw transmission assembly; and a thermal error prediction and compensation controller is arranged in the numerical control table. The device has the beneficial effects that the temperature sensors are arranged on the bearing seats and the nuts at the two ends of the ball screw, temperature and thermal errors of the ball screw in the X direction, the Y direction and the Z direction are measured synchronously through the back-and-forth movement of the nuts on the ball screw, multiple sets of data are transmitted to the thermal error prediction and compensation controller, and the temperature and thermal errors of the ball screw in the X direction, the Y direction and the Z direction are predicted and compensated. Data is provided for calculation of thermal error real-time compensation; by changing the ball screws with different length specifications, a relation test of temperature and thermal error can be carried out on the ball screws with different specifications, and linear thermal error prediction and compensation can also be carried out on a single screw.

Description

Technical Field

[0001] This invention belongs to the field of measurement technology for processing equipment, and in particular relates to a test bench for lead screws of vertical and horizontal five-sided machining centers with automatic temperature compensation. Background Technology

[0002] A ball screw drive system refers to a helical transmission component consisting of a ball screw and a nut. It is a precision transmission device that converts rotary motion into linear motion. Ball screw and nut assemblies are commonly used transmission components in mechanical systems and are widely applied in machining centers. A temperature detection and compensation device for ball screws is used to measure the thermal elongation of the ball screw and achieve real-time compensation for thermal errors. It is mainly used for measuring and compensating for thermal deformation of ball screws in high-precision equipment such as precision CNC machine tools to improve transmission and positioning accuracy.

[0003] For the machining characteristics of vertical and horizontal composite five-axis machining centers, parts are typically machined simultaneously using both vertical and horizontal spindles. The ball screw drive assembly of these centers usually operates under varying temperature conditions. Due to the slender shaft of the screw, it is prone to thermal deformation, leading to thermal displacement errors. When the ball screw nuts move simultaneously in the X, Y, and Z directions, the slender shaft undergoes thermal expansion and contraction, resulting in thermal elongation. These thermal errors in the three directions couple with each other, causing nonlinear thermal coupling errors. Traditional ball screw thermal deformation measurement and error compensation techniques struggle to accurately measure nonlinear thermal coupling errors, thus making real-time compensation for the nonlinear thermal errors generated by the coupling between the X, Y, and Z axes difficult.

[0004] Therefore, there is an urgent need for a new ball screw test bench to accurately measure the thermal error generated when the ball screw nut moves simultaneously in the X, Y, and Z directions, to provide data support for the calculation method of real-time compensation value of thermal error, thereby improving machining and positioning accuracy. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a vertical and horizontal five-sided machining center lead screw test bench with automatic temperature compensation.

[0006] This vertical and horizontal five-sided machining center ball screw test bench with automatic temperature compensation includes: a base, a worktable and a CNC table. The worktable includes a horizontal worktable, a vertical worktable and a column. The horizontal worktable and the vertical worktable are both horizontally set on the base. Screw transmission components are respectively installed in the worktable. The CNC table is equipped with a thermal error prediction and compensation controller. The lead screw drive assembly includes a servo motor, a lead screw, a nut, and a coupling. The two ends of the lead screw are respectively connected to a first bearing housing and a second bearing housing. The second bearing housing is equipped with a coupling. The lead screw is connected to the servo motor through the coupling. The nut is located on the lead screw. When the lead screw rotates, the nut moves along the lead screw axis. A slider is fixed on the nut. The column is perpendicular to the base, and the column moves along the lead screw of the longitudinal worktable with the nut; Multiple mounting holes are provided along the axial direction of the lead screw inside the worktable. The first bearing seat and the second bearing seat are respectively provided with mounting holes. The first bearing seat and the second bearing seat are fixed to the mounting holes of the worktable according to the length of the lead screw. Temperature sensors with displacement signal detection function are provided on the first bearing seat, the second bearing seat and the nut respectively. The temperature sensors are connected to the thermal error prediction and compensation controller.

[0007] Preferably, the first bearing housing and the second bearing housing are connected to the end of the lead screw by a locking nut, and the outer end faces of the first bearing housing and the second bearing housing along the axial direction of the lead screw are provided with anti-collision rubber.

[0008] Preferably, the lead screw drive assembly includes an X-axis lead screw drive assembly, a Y-axis lead screw drive assembly, and a Z-axis lead screw drive assembly. The X-axis lead screw drive assembly, the Y-axis lead screw drive assembly, and the Z-axis lead screw drive assembly are respectively located in the transverse worktable, the longitudinal worktable, and the column. The lead screws in the X-axis lead screw drive assembly, the Y-axis lead screw drive assembly, and the Z-axis lead screw drive assembly are respectively the X-axis ball screw, the Y-axis ball screw, and the Z-axis ball screw. The Y-axis ball screw nut has a support frame via a slider, and a column is vertically fixed on the support frame; the CNC table is fixedly connected to an L-shaped column, and the L-shaped column is fixed to the slider on the X-axis ball screw nut; the transverse worktable and the longitudinal worktable are provided with grooves on both sides of the screw axis, and the L-shaped column and the support frame are respectively connected to the grooves of the transverse worktable and the longitudinal worktable. Servo motors include X-axis motors, Y-axis motors, and Z-axis motors.

[0009] Preferably, the temperature sensor includes a first temperature sensor, a second temperature sensor, and a nut temperature sensor. The first temperature sensor and the second temperature sensor are respectively installed on the first bearing housing and the second bearing housing, and the nut temperature sensor is installed on the nut.

[0010] The method of using this ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation includes the following steps: Step 1: Selecting key heat source points: Start the servo motor to rotate the lead screw, and the nut temperature sensor in the nut measures the temperature at various positions on the lead screw. Based on the measurement results, select several key heat source points on the lead screw. Step 2: Collect training samples: Restart the servo motor to make the lead screw drive assembly run, set the nut to move back and forth along the lead screw and stay at each heat source key point for 1 to 3 seconds, detect the temperature value and thermal error value of the heat source key point through the nut temperature sensor, and organize it into temperature rise time series data; Step 3, Prediction Model and Training: Establish a thermal error prediction model based on the SA-LSTM-TCN hybrid network structure, and train it using the temperature rise time series data obtained in Step 2; Step 4: Predict thermal error: The nut temperature sensor detects the temperature value at the location of the nut in real time and inputs it into the trained thermal error prediction model based on the SA-LSTM-TCN hybrid network structure to obtain the predicted thermal error value. Step 5: Real-time compensation: Set the compensation translation amounts for the X, Y, and Z axes based on the predicted thermal error values. Control the translation of the nut through the thermal error prediction and compensation controller to achieve real-time thermal error compensation.

[0011] As a preferred option, in step one, after measuring the temperature at various positions of the lead screw using a nut temperature sensor, several points on the lead screw with the largest temperature increase are selected as key heat source points. In step two, at least 100 sets of temperature values ​​and thermal error values ​​of key points of the heat source are collected, that is, the nut moves back and forth along the screw at least 50 times, and the temperature values ​​and thermal error values ​​obtained by the first temperature sensor and the second temperature sensor are also collected.

[0012] Preferably, in step four, the X-axis motor is started, and the thermal error prediction value corresponding to the temperature value at the location of the nut on the X-axis ball screw is obtained through the trained thermal error prediction model based on the SA-LSTM-TCN hybrid network structure. The thermal error prediction value includes the thermal error prediction value of the X-axis ball screw. .

[0013] Preferably, in step four, the Y-axis motor and Z-axis motor are started simultaneously, driving the Y-axis ball screw and Z-axis ball screw to rotate respectively. The Z-axis ball screw, along with the column and support frame, reciprocates on the longitudinal worktable. The nut temperature sensors on the Y-axis and Z-axis ball screws simultaneously measure the temperature. Then, a thermal error prediction and compensation controller is used to predict and compensate for the nonlinear coupling thermal error of the X-axis, Y-axis, and Z-axis ball screws in real time. The predicted thermal error values ​​for the Y-axis and Z-axis ball screws are... and ; In step five, the compensation translation amounts for the axial displacement of the nuts on the X-axis ball screw, Y-axis ball screw, and Z-axis ball screw are respectively as follows: , and .

[0014] The beneficial effects of this invention are: 1) This invention features temperature sensors on both the bearing housings and nuts at both ends of the ball screw. Utilizing the reciprocating motion of the nuts on the ball screw, the temperature and thermal error of the ball screw in the X, Y, and Z directions are measured simultaneously. This allows for precise measurement of the nonlinear thermal coupling error resulting from the coupling of thermal errors in the three directions, and transmits multiple sets of data to the thermal error prediction and compensation controller, providing data for real-time thermal error compensation calculations. Furthermore, this test bench allows for the replacement of the ball screw. By interfering with the first and second bearing housings and fixing them to the mounting holes on the worktable, and then securing them with locking nuts, ball screws of different lengths and specifications can be used to conduct temperature and thermal error relationship tests on ball screws of different specifications. Alternatively, linear thermal error prediction and compensation can be performed on a single screw.

[0015] 2) This invention incorporates a temperature compensation function for the ball screw nut transmission, enabling real-time compensation for thermal elongation of the ball screw in the X, Y, and Z axes. By constructing a thermal error prediction model based on an SA-LSTM-TCN hybrid network structure, the required displacement of the ball screw transmission under real-time temperature is calculated. The compensation value is calculated in real-time based on temperature sensor data, and finally, real-time compensation is performed. This invention improves the transmission and positioning accuracy of the precision ball screw nut by detecting, predicting, and compensating for ball screw thermal errors. By supplementing the real-time temperature of the screw, it overcomes the displacement error caused by temperature rise, resulting in higher positioning and transmission accuracy. Attached Figure Description

[0016] Figure 1 A three-dimensional view of the ball screw test bench; Figure 2 This is a sectional view of the ball screw test bench; Figure 3 This is a side view of the ball screw test bench; Figure 4 Schematic diagram of thermal error prediction and compensation principle for ball screws; Figure 5 A distribution diagram of temperature rise measurement points on the ball screw shaft; Figure 6 This is a schematic diagram of a thermal error prediction model based on a hybrid network structure of SA-LSTM-TCN.

[0017] Explanation of reference numerals in the attached drawings: Base 1, Horizontal worktable 2, Vertical worktable 3, X-axis motor 4, X-axis ball screw 5, Nut 6, Support frame 7, Column 8, CNC table 9, First bearing seat 10, Second bearing seat 11, First bearing assembly 12, Second bearing assembly 13, Coupling 14, Locking nut 15, Anti-collision rubber 16, Thermal error prediction and compensation controller 17, First temperature sensor 18, Second temperature sensor 19, Nut temperature sensor 20, Slider 21, Z-axis ball screw 22, Vertical worktable 23, Y-axis ball screw 24, L-shaped column 25, Y-axis motor 26, Z-axis motor 27. Detailed Implementation

[0018] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that those skilled in the art can make several modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0019] Example 1 As one example, such as Figures 1 to 3 As shown, a ball screw test bench for vertical and horizontal five-sided machining center with automatic temperature compensation includes: a base 1, a worktable and a CNC table 9. The worktable includes a horizontal worktable 2, a vertical worktable 3 and a column 8. The horizontal worktable 2 and the vertical worktable 3 are both horizontally arranged on the base 1. Screw transmission components are respectively provided in the worktable. The lead screw drive assembly includes an X-axis lead screw drive assembly, a Y-axis lead screw drive assembly, and a Z-axis lead screw drive assembly. The X-axis lead screw drive assembly, the Y-axis lead screw drive assembly, and the Z-axis lead screw drive assembly are respectively located in the transverse worktable 2, the longitudinal worktable 3, and the column 8. The internal structure and connection method of the X-axis lead screw drive assembly, the Y-axis lead screw drive assembly, and the Z-axis lead screw drive assembly are basically the same, except that the lead screws are X-axis ball screw 5, Y-axis ball screw 24, and Z-axis ball screw 22, respectively, and the X-axis ball screw 5, Y-axis ball screw 24, and Z-axis ball screw 22 are perpendicular to each other.

[0020] All lead screw drive components include a servo motor, lead screw, nut 6, coupling 14, locking nut 15, and anti-collision rubber 16. The two ends of the lead screw are respectively connected to a first bearing seat 10 and a second bearing seat 11. The first bearing seat 10 and the second bearing seat 11 are connected to the end of the lead screw by the locking nut 15. The first bearing seat 10 and the second bearing seat 11 are provided with anti-collision rubber 16 on the outer end face along the axial direction of the lead screw. There are preset holes between the anti-collision rubber 16 and the bearing seat, and the two are fixed by bolts.

[0021] The servo motors include X-axis motor 4, Y-axis motor 26, and Z-axis motor 27.

[0022] The second bearing housing 11 is equipped with a coupling 14. The lead screw is connected to the motor through the coupling 14. The nut 6 is located on the lead screw 5. When the lead screw rotates, the nut 6 moves along the lead screw axis. A slider 21 is fixed on the nut 6. A support frame 7 is fixedly connected to the nut 6 of the Y-axis ball screw 24 via a slider 21. A column 8 is vertically fixed on the support frame 7, making the column 8 perpendicular to the base 1. The column 8 moves along the screw of the longitudinal worktable 3 with the nut 6.

[0023] The CNC table 9 is fixed on the L-shaped column 25, and the L-shaped column 25 and the X-axis slider 2121 on the X-axis ball screw 5 nut 6 are fixed; the transverse worktable 2 and the longitudinal worktable 3 are provided with slide grooves on both sides of the screw axis, and the two sides of the L-shaped column 25 and the support frame 7 are respectively connected to the slide grooves of the transverse worktable 2 and the longitudinal worktable 3.

[0024] Temperature sensors with displacement signal detection function are respectively provided on the first bearing housing 10, the second bearing housing 11 and the nut 6. These temperature sensors can simultaneously measure temperature and displacement values, and the thermal error value can be obtained by calculating the displacement value and the screw specification parameters.

[0025] Example 2 Based on Example 1, Example 2 proposes a more specific ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation.

[0026] The CNC console 9 is equipped with a thermal error prediction and compensation controller 17, a CNC system and its hardware and software. The thermal error prediction and compensation controller 17 is a thermal error prediction and compensation controller, which is loaded with a thermal error prediction model based on the SA-LSTM-TCN hybrid network structure and software for sending thermal error compensation commands. It can directly control the operation of the motors in the transverse worktable 2, the longitudinal worktable 3 and the column 8 to realize thermal error compensation of the X-axis, Y-axis and Z-axis ball screw transmission.

[0027] The base 1 has an inclined surface, which facilitates human-machine interaction and makes it easy to operate the CNC table 9. It also facilitates the installation and removal of the thermal error prediction and compensation controller 17 inside the CNC table 9.

[0028] The temperature sensor includes a first temperature sensor 18, a second temperature sensor 19, and a nut temperature sensor 20. The first temperature sensor 18 and the second temperature sensor 19 are respectively installed on the first bearing housing 10 and the second bearing housing 11, and the nut temperature sensor 20 is installed on the nut 6. Blind holes are opened in the mounting positions of the temperature sensors on the first bearing housing 10, the second bearing housing 11, and the nut 6 to serve as mounting holes for the temperature sensors. All the temperature sensors are fixed by being inserted into the corresponding mounting holes through interference fit.

[0029] The first temperature sensor 18 and the second temperature sensor 19 can measure the temperature and thermal error at both ends of the lead screw in real time. The nut temperature sensor 20 on the nut 6 can move back and forth on the lead screw with the nut 6. When the nut 6 moves to a certain position on the lead screw, the nut temperature sensor 20 detects the temperature value of the nut 6, which can represent the temperature of the lead screw at that position.

[0030] All temperature sensors are connected to the thermal error prediction and compensation controller 17.

[0031] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 1 can be referred to each other, and will not be repeated in this application.

[0032] Example 3 As another embodiment, the method of using the ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation in Embodiment 2 is as follows: Figure 4 As shown, it includes the following steps: Step 1: Selection of Key Heat Sources: Start the X-axis motor 4, Y-axis motor 26, and Z-axis motor 27 to rotate the X-axis ball screw 5, Y-axis ball screw 24, and Z-axis ball screw 22. The three nuts 6 move back and forth on their respective screws. Simultaneously, the nut temperature sensor 20 measures the temperature at various points on the screws. Then, select the seven points on each screw with the largest temperature increase as key heat source points, such as... Figure 5 As shown, M2 to 4 and M7 to 9 are respectively, and the positions of the first temperature sensor 18 and the second temperature sensor 19 are set as M1 and M10, respectively. The nut temperature sensor 20 is set at position M6 on the nut 6. The position of M6 moves with the movement of the nut 6, so it represents the temperature of the nut 6 itself and its location.

[0033] Step 2: Collect training samples: Restart the servo motor to make the lead screw drive assembly run, set the nut 6 to move back and forth along the lead screw and stop at each heat source key point for 1-3 seconds, so that the temperature on the lead screw is transferred to the nut 6. The temperature value and thermal error value of the heat source key point are detected by the nut temperature sensor 20. Collect at least 100 sets of temperature values ​​and thermal error values ​​of the heat source key points, that is, the nut 6 moves back and forth along the lead screw at least 50 times; and organize them into temperature rise time series data to provide sufficient training samples for the training of the prediction model.

[0034] Step 3: Prediction Model and Training: Establish a thermal error prediction model based on the SA-LSTM-TCN hybrid network structure, and train it using the temperature rise time series data obtained in Step 2; for example... Figure 6As shown, based on Variational Mode Decomposition (VMD), the one-dimensional temperature rise time series data is decomposed into two sets of two-dimensional matrices according to high frequency and low frequency. The sliding window acquisition time period is set to 60s, and the translation length is 1s. Specifically, VMD is used to decompose the temperature rise time series data into feature data with 8 channels. The 8-channel input data is divided into 4 channels of high-frequency data and 4 channels of low-frequency data according to frequency, which are used as input data for the SA-LSTM-TCN hybrid network structure. The SA-LSTM-TCN hybrid network structure includes a parallel high-frequency feature extraction module and a low-frequency feature extraction module to realize the simultaneous extraction of spatial and temporal features of the temperature rise data. The spatial characteristics refer to the nonlinear properties formed by the mutual coupling of thermal errors in each axis.

[0035] Step 4: Predicting Thermal Error: The trained thermal error prediction model based on the SA-LSTM-TCN hybrid network structure is applied to the engineering process. In engineering applications, the temperature sensor on nut 6 may not have displacement detection functionality, but only detects the temperature of the lead screw at its location. When nut 6 moves to a certain position on the lead screw for machining, the nut temperature sensor 20 detects the temperature value at that position in real time. Alternatively, the actual temperature data at this position can be obtained through other means and input into the trained thermal error prediction model based on the SA-LSTM-TCN hybrid network structure to obtain the predicted thermal error value for that point. The predicted thermal error values ​​include the predicted thermal error values ​​for the X-axis ball screw 5, Y-axis ball screw 24, and Z-axis ball screw 22, which are respectively... , and ; Step 5: Real-time Compensation: The controller calculates the compensation amount for axial displacement on the X, Y, and Z axes in real time based on the predicted thermal error value. The compensation amounts for axial displacement on the X, Y, and Z axes correspond to the following values: , and The displacement of the nut 6 on the lead screw is controlled by the thermal error prediction and compensation controller 17, and the compensation amount changes with the temperature of the lead screw at the location of the nut 6, thereby achieving accurate real-time thermal error compensation.

[0036] Example 4 Based on Example 3, Example 4 presents a more specific method for using a ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation.

[0037] In step three, such as Figure 6 As shown, the high-frequency feature extraction module extracts the spatiotemporal information of the high-frequency sequence through a series of SA and TCN modules, while the low-frequency feature extraction module extracts the spatiotemporal information of the low-frequency sequence through a series of SA and LSTM modules. Feature fusion is then performed on the spatiotemporal information of the high-frequency sequence and the low-frequency sequence.

[0038] In the SA-LSTM-TCN serial-parallel composite network, the SA and TCN modules are serially connected to extract the spatiotemporal information of high-frequency sequences, while the SA and LSTM modules are serially connected to extract the spatiotemporal information of low-frequency sequences. The high-frequency and low-frequency feature extraction modules are then connected in parallel for feature fusion. Specific construction steps: First, the query vector dimension and key vector dimension of the SA module need to be kept consistent at 64, and the value vector dimension is 256 to capture more spatial features. The input vector is mapped to query vector, key vector and value vector through linear transformation. The value vector and attention weight are weighted and summed to obtain the output vector of the self-attention mechanism. Figure 6 In the text, 60 represents the time setting for the sliding window.

[0039] In the TCN module, four residual blocks are connected in series. Each residual block uses two layers of dilated causal convolution with a kernel size of 3, a number of kernels of 256, and a dilation factor of 2 to capture the local and global time features of the time series data. Each residual block uses residual connections to fuse the input and output of the residual block to solve the problems of gradient vanishing and gradient exploding.

[0040] In the LSTM module, there are 256 hidden units and 1 hidden layer. Based on the results of the input and forget gates, the contents of the memory cells are updated. The opening degree of the output gate is calculated using the current input and the hidden state of the previous time step. Combining the output gate and the contents of the memory cells, the hidden state of the current time step is calculated as the output. Channel concatenation merges the outputs of the two spatiotemporal extraction modules, combining the temporal and channel dimensions. Then, two fully connected layers with 512 and 64 units respectively are concatenated, along with an output layer with a ReLU activation function and a single output dimension.

[0041] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 3 can be referred to each other, and will not be repeated in this application.

[0042] Example 5 This fifth embodiment proposes that, using the method described in the fourth embodiment, the thermal error of lead screws of different specifications and quantities can also be measured and predicted.

[0043] The workbench has multiple mounting holes along the screw axis. The first bearing seat 10 and the second bearing seat 11 each have several mounting holes. The first bearing seat 10 and the second bearing seat 11 are fixed to the mounting holes on the workbench according to the screw length with an interference fit. With the help of the locking nut 15, the disassembly and installation of ball screws of different lengths can be realized. Therefore, it can be used for the testing of screws of different lengths.

[0044] For ball screws of different lengths, simply switch them to a ball screw test bench of a vertical and horizontal five-sided machining center with automatic temperature compensation, and repeat the above steps to obtain the corresponding thermal error prediction model based on the SA-LSTM-TCN hybrid network structure. Applying this model to engineering projects will enable thermal error prediction and compensation for ball screws of this length.

[0045] Alternatively, lead screws can be installed only in the transverse worktable 2, the longitudinal worktable 3, or the column 8 to perform linear thermal error prediction and compensation for a single lead screw.

[0046] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from the others. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation, characterized in that, include: The base (1), worktable and CNC table (9) include a horizontal worktable (2), a vertical worktable (3) and a column (8). The horizontal worktable (2) and the vertical worktable (3) are both horizontally set on the base (1). The worktable is equipped with a lead screw drive assembly. The CNC table (9) is equipped with a thermal error prediction and compensation controller (17). The lead screw drive assembly includes a servo motor, a lead screw, a nut (6), and a coupling (14). The two ends of the lead screw are respectively connected to a first bearing seat (10) and a second bearing seat (11). The second bearing seat (11) is equipped with a coupling (14). The lead screw is connected to the servo motor through the coupling (14). The nut (6) is located on the lead screw (5). When the lead screw rotates, the nut (6) moves along the lead screw axis. A slider (21) is fixed on the nut (6). The column (8) is perpendicular to the base (1), and the column (8) moves along the lead screw of the longitudinal worktable (3) with the nut (6); Multiple mounting holes are provided along the screw axis inside the worktable. Mounting holes are provided on the first bearing seat (10) and the second bearing seat (11). The first bearing seat (10) and the second bearing seat (11) are fixed to the mounting holes on the worktable according to the screw length. Temperature sensors with displacement signal detection function are provided on the first bearing seat (10), the second bearing seat (11) and the nut (6). The temperature sensors are connected to the thermal error prediction and compensation controller (17).

2. The ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation as described in claim 1, characterized in that: The first bearing housing (10) and the second bearing housing (11) are connected to the end of the lead screw by locking nut (15). The first bearing housing (10) and the second bearing housing (11) are provided with anti-collision rubber (16) on the outer end face along the axial direction of the lead screw.

3. The ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation as described in claim 1, characterized in that: The lead screw drive assembly includes an X-axis lead screw drive assembly, a Y-axis lead screw drive assembly, and a Z-axis lead screw drive assembly. The X-axis lead screw drive assembly, the Y-axis lead screw drive assembly, and the Z-axis lead screw drive assembly are respectively located in the transverse worktable (2), the longitudinal worktable (3), and the column (8). The lead screws in the X-axis lead screw drive assembly, the Y-axis lead screw drive assembly, and the Z-axis lead screw drive assembly are respectively the X-axis ball screw (5), the Y-axis ball screw (24), and the Z-axis ball screw (22). The nut (6) of the Y-axis ball screw (24) is provided with a support frame (7) via a slider (21), and a column (8) is vertically fixed on the support frame (7); the CNC table (9) is fixedly connected to an L-shaped column (25), and the L-shaped column (25) is fixed to the slider (21) on the nut (6) of the X-axis ball screw (5); the transverse worktable (2) and the longitudinal worktable (3) are provided with grooves on both sides of the screw axis, and the sides of the L-shaped column (25) and the support frame (7) are respectively connected to the grooves of the transverse worktable (2) and the longitudinal worktable (3); The servo motors include an X-axis motor (4), a Y-axis motor (26), and a Z-axis motor (27).

4. The ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation as described in claim 1, characterized in that: The temperature sensor includes a first temperature sensor (18), a second temperature sensor (19) and a nut temperature sensor (20). The first temperature sensor (18) and the second temperature sensor (19) are respectively installed on the first bearing housing (10) and the second bearing housing (11), and the nut temperature sensor (20) is installed on the nut (6).

5. The method of using the ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Step 1: Selecting key heat source points: Start the servo motor to make the lead screw rotate. The nut temperature sensor (20) in the nut (6) measures the temperature at each position of the lead screw. Based on the measurement results, select several key heat source points on the lead screw. Step 2: Collect training samples: Restart the servo motor to make the lead screw drive assembly run, set the nut (6) to move back and forth along the lead screw and stay at each heat source key point for 1 to 3 seconds, detect the temperature value and thermal error value of the heat source key point through the nut temperature sensor (20), and organize it into temperature rise time series data; Step 3, Prediction Model and Training: Establish a thermal error prediction model based on the SA-LSTM-TCN hybrid network structure, and train it using the temperature rise time series data obtained in Step 2; Step 4: Predict thermal error: The nut temperature sensor (20) detects the temperature value at the location of the nut (6) in real time and inputs it into the trained thermal error prediction model based on the SA-LSTM-TCN hybrid network structure to obtain the predicted thermal error value. Step 5: Real-time compensation: Set the compensation translation amount of the X-axis, Y-axis and Z-axis according to the thermal error prediction value, and control the translation of the nut (6) through the thermal error prediction and compensation controller (17) to realize real-time thermal error compensation.

6. The method of using the ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation as described in claim 5, characterized in that, In step one, after measuring the temperature at each position of the lead screw using the nut temperature sensor (20), several points on the lead screw with the largest temperature increase are selected as key heat source points. In step two, at least 100 sets of temperature values ​​and thermal error values ​​of key points of the heat source are collected, that is, the nut (6) moves back and forth along the screw at least 50 times, and the temperature values ​​and thermal error values ​​obtained by the first temperature sensor (18) and the second temperature sensor (19) are also collected.

7. The method of using the ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation as described in claim 5, characterized in that, In step four, the X-axis motor (4) is started, and the thermal error prediction value corresponding to the temperature value of the nut (6) on the X-axis ball screw (5) is obtained through the trained thermal error prediction model based on the SA-LSTM-TCN hybrid network structure. The thermal error prediction value includes the thermal error prediction value of the X-axis ball screw (5). .

8. The method of using the ball screw test bench for vertical and horizontal five-sided machining centers with automatic temperature compensation as described in claim 7, characterized in that, In step four, the Y-axis motor (26) and Z-axis motor (27) are started simultaneously to drive the Y-axis ball screw (24) and Z-axis ball screw (22) to rotate respectively. The Z-axis ball screw (22), together with the column (8) and support frame (7), moves back and forth on the longitudinal worktable (3). The nut temperature sensors (20) on the Y-axis ball screw (24) and Z-axis ball screw (22) measure the temperature simultaneously. Then, the nonlinear coupling thermal error of the X-axis ball screw (5), Y-axis ball screw (24) and Z-axis ball screw (22) is predicted and compensated in real time by the thermal error prediction and compensation controller (17). The predicted thermal error values ​​of the Y-axis ball screw (24) and Z-axis ball screw (22) are... and ; In step five, the compensation translation amounts for the axial displacement of the nut (6) on the X-axis ball screw (5), Y-axis ball screw (24), and Z-axis ball screw (22) are respectively as follows: , and .

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