Elastic structural body anti-swing motion control experiment platform and test method

Abstract

The invention belongs to the technical field of equipment testing and experimental platforms, and relates to an elastic structural body anti-swing motion control experimental platform and a testing method.The platform generates a position sequence through upper computer trajectory planning software and drives a servo execution mechanism to drive an elastic structural body to apply excitation in the Z-axis lifting direction (vertical direction); a laser displacement sensor is used for collecting displacement data of the tail end in the Z-axis direction, and data collecting and processing software is used for completing synchronous recording, feature extraction and evaluation output; the platform comprises a supporting frame, a servo driving system, a flexible beam elastic load module and a laser displacement measurement module, and is used for supporting tail end jitter rule research and parameter identification evaluation.

Description

Technical Field

[0001] This invention belongs to the technical field of equipment testing and experimental platforms, and relates to an experimental platform for studying anti-shaking methods during the motion of elastic structures. The platform generates a position sequence through upper computer trajectory planning software and drives a servo actuator to apply excitation to the elastic structure along the Z-axis lifting direction (vertical direction). A laser displacement sensor is used to collect displacement data of the end effector along the Z-axis direction, and the data acquisition and processing software completes synchronous recording, feature extraction, and evaluation output. The platform includes a support frame, a servo drive system, a flexible beam elastic load module, and a laser displacement measurement module, which are used for studying the shaking law of the support end effector and evaluating parameters. Background Technology

[0002] During vertical lifting operations, equipment such as bridge cranes, vacuum robots, and high-speed pick-and-place machines are prone to residual vibration (end-effector jitter) in their elastic components due to factors like lightweight design, increased slenderness ratio, and transmission flexibility. This jitter reduces positioning accuracy and repeatability, causing placement misalignment, mounting errors, and even affecting process consistency. Therefore, anti-shake / anti-jitter strategies are typically employed in servo control and trajectory planning to suppress vibration. Existing anti-jitter methods include input shaping, acceleration / deceleration curve and trajectory optimization, feedforward compensation, and feedback vibration suppression control. However, due to significant differences in structural types and boundary conditions, substantial variations in modal parameters with load and operating conditions, and high sensitivity of algorithm parameters to the object, cross-device reproduction and horizontal comparison are difficult. Furthermore, the lack of a unified system for excitation application, synchronous acquisition, and quantitative evaluation hinders the formation of a universally verifiable platform, restricting the systematic research and engineering transformation of anti-jitter methods. Therefore, a universal experimental platform is needed to acquire end-effector displacement under Z-axis motion excitation and perform feature extraction and effect evaluation, thereby supporting research on anti-jitter methods. Summary of the Invention

[0003] To address the aforementioned issues, this invention presents an experimental platform for studying anti-shaking methods during the motion of elastic structures. This platform generates a position sequence using host computer trajectory planning software and drives a servo actuator to excite the elastic structure along the Z-axis vertical direction. A laser displacement sensor collects displacement data of the end-effector along the Z-axis, and data acquisition and processing software performs synchronous recording, feature extraction, and evaluation output. The platform includes a support frame, a servo drive system, a flexible beam elastic load module, and a laser displacement measurement module. It is used for studying the shaking patterns and parameter identification and evaluation of the end-effector, thereby selecting an anti-shaking control method that can effectively eliminate the shaking at the end of the elastic structure.

[0004] The present invention adopts the following technical solution: An experimental platform for anti-sway motion control of an elastic structure includes a support, a servo drive system, an elastic structure, a lead screw 4, a lead screw nut 5, a slider 6, a guide rail 7, a laser displacement sensor 8, a long rod 9, and a host computer. The support frame provides support for other components of the entire experimental platform, including the lower frame and the upper vertical plate; Furthermore, the lower frame of the bracket is constructed from the upper and lower bases and the supporting frame 12 between the upper and lower bases, and the upper vertical plate is vertically fixed to the upper base.

[0005] The servo drive system is used to apply excitation motion according to the planned trajectory, and includes a servo motor 21 and a servo driver 22 fixed in the lower frame; the servo motor 21 and the servo driver 22 are electrically connected; the output shaft of the servo motor 21 is fixedly connected to the lead screw 4. Furthermore, the servo driver 22 is fixed to the lower base, and the servo motor 21 is fixed to the upper base.

[0006] The guide rail 7 is vertically fixed on both sides of the upper vertical plate in the bracket; the slider 6 is installed on the guide rail 7 and moves up and down along the guide rail 7 as the lead screw 4 rotates. The lead screw 4 is arranged vertically and located between the two guide rails 7; The elastic structure includes a flexible beam 31, a horizontal plate, and a clamping mounting base 32. The two ends of the horizontal plate are fixed to two sliders 6 on the guide rail 7 by the clamping mounting base 32, and the middle part of the horizontal plate is fixed to the lead screw nut 5. The flexible beam 31 is set perpendicular to the horizontal plate, and its plane remains horizontal when the flexible beam 31 is static. The flexible beam 31 is used to generate an elastic response under excitation. Furthermore, a reinforcing plate is arranged in a triangle between the cross plate and the end of the flexible beam 31 near the lead screw.

[0007] The laser displacement sensor 8 is located on the lower side of the end of the flexible beam 31 and is fixed on the bracket by a long rod 9; The host computer is connected to the servo driver 22 and the laser displacement sensor 8 respectively, and collects information from both. Based on the collected information, the end effector jitter characteristics are obtained.

[0008] Furthermore, a host computer software system is configured, including a trajectory planning module and a data acquisition and processing module. The trajectory planning module outputs the position sequence and sends it to the servo drive system. The data acquisition and processing module is used to acquire the signal detected by the laser displacement sensor 8 and process the data in the host computer.

[0009] A method for detecting end-point jitter, the specific steps of which are as follows: Step 1: The host computer outputs the trajectory in the form of a position sequence and drives the servo motor 21 to apply excitation; Step 2: The servo motor 21 rotates, which drives the lead screw 4 to rotate. The lead screw nut 5 drives the elastic structure to move vertically along the guide rail 7 according to the trajectory output by the host computer. Step 3: The laser displacement sensor 8 aligns with the end of the flexible beam 31 and collects displacement data; Step 4: The laser displacement sensor 8 uploads the collected displacement data to the host computer and outputs the displacement data at the end of the flexible beam 31; Step 5: Calculate the end jitter indicators (peak-to-peak value, dominant frequency, settling time, etc.) based on the displacement data and output the evaluation results.

[0010] Compared with the prior art, the present invention has at least the following advantages: it uses a laser displacement sensor to perform non-contact measurement of the end displacement, avoiding the influence of additional mass and installation stress on the inherent characteristics of the system; the host computer outputs the excitation trajectory in the form of a position sequence, which facilitates control reproduction and experimental repeatability; the natural frequency working condition can be configured by replacing the flexible beam group, which facilitates the system to compare the correspondence between "working condition - excitation - jitter index"; the jitter index output is standardized (peak-to-peak value, dominant frequency, settling time, etc.), which can be used for verification such as control parameter tuning and structural comparison. Attached Figure Description

[0011] Figure 1 This is an overall flowchart of the present invention; Figure 2 This is a front view of the overall structure of the experimental platform of the present invention. Figure 3 This is a side view of the overall structure of the experimental platform of the present invention; Figure 4 This is a top view of the elastic structure (flexible beam and clamping mounting base). Figure 5 This is a front view of the elastic structure (flexible beam and clamping mounting base); Figure 6 This is a three-dimensional view of the overall structure of the experimental platform of this invention.

[0012] In the diagram: 11-Base; 12-Support frame; 21-Servo motor; 22-Servo driver; 31-Flexible beam; 32-Clamping mounting base; 4-Lead screw; 5-Lead screw nut; 6-Slider; 7-Guide rail; 8-Laser displacement sensor; 9-Long rod. Detailed Implementation

[0013] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0014] like Figure 6 As shown, an experimental platform was built, and the following tests were conducted: An experimental platform for anti-sway motion control of an elastic structure includes a support, a servo drive system, an elastic structure, a lead screw 4, a lead screw nut 5, a slider 6, a guide rail 7, a laser displacement sensor 8, a long rod 9, and a host computer. The support frame provides support for other components of the entire experimental platform, including a lower frame and an upper vertical plate. The lower frame of the support frame is constructed from upper and lower bases and a support frame 12 between the upper and lower bases, and the upper vertical plate is vertically fixed to the upper base.

[0015] The servo drive system is used to apply excitation motion according to the planned trajectory, including a servo motor 21 and a servo driver 22 fixed in the lower frame; the servo motor 21 and the servo driver 22 are electrically connected; the output shaft of the servo motor 21 is fixedly connected to the lead screw 4; the servo driver 22 is fixed to the lower base, and the servo motor 21 is fixed to the upper base.

[0016] The guide rail 7 is vertically fixed on both sides of the upper vertical plate in the bracket; the slider 6 is installed on the guide rail 7 and moves up and down along the guide rail 7 as the lead screw 4 rotates. The lead screw 4 is arranged vertically and located between the two guide rails 7; The elastic structure includes a flexible beam 31, a horizontal plate, and a clamping mounting base 32. The two ends of the horizontal plate are fixed to two sliders 6 on the guide rail 7 by the clamping mounting base 32, and the middle part of the horizontal plate is fixed to the lead screw nut 5. The flexible beam 31 is set perpendicular to the horizontal plate, and its plane remains horizontal when the flexible beam 31 is static. The flexible beam 31 is used to generate an elastic response under excitation. A reinforcing plate is arranged in a triangle between the horizontal plate and the end of the flexible beam 31 near the lead screw.

[0017] The laser displacement sensor 8 is located on the lower side of the end of the flexible beam 31 and is fixed on the bracket by a long rod 9; The host computer is connected to the servo driver 22 and the laser displacement sensor 8, respectively, to collect information from both and obtain the end effector jitter characteristics based on the collected information. The host computer software system includes a trajectory planning module and a data acquisition and processing module. The trajectory planning module outputs the position sequence and sends it to the servo drive system. The data acquisition and processing module is used to acquire the signal detected by the laser displacement sensor 8 and process the data in the host computer.

[0018] A method for detecting end-point jitter, the specific steps of which are as follows: The detection method is applied as follows: A set of standard position sequence trajectories for comparison and evaluation (e.g., displacement sequence corresponding to trapezoidal velocity, S-curve displacement sequence) is pre-set in the host computer software system, and uniform parameters such as stroke, velocity, and acceleration are set so that different parameters can be compared under the same working conditions; the host computer sends out the position sequence, driving the servo motor 21 to drive the lead screw 4, lead screw nut 5, and slider 6, so that the elastic structure completes the lifting and lowering motion along the Z-axis; the laser displacement sensor 8 is aligned with the end of the flexible beam 31 and collects displacement data, which is uploaded to the host computer to generate the end displacement response curve; the host computer processes the displacement data, calculates the end jitter index, and the maximum jitter amplitude. , main frequency (Reflecting the main vibration frequency band), settling time (Reflects the time required for jitter to decay to the threshold). This is obtained by applying different trajectory planning strategies under the same standard operating conditions. , , Compare the results. Use the maximum vibration amplitude. The preferred solution is the one that is smaller, has a shorter stabilization time, and meets the constraints, so as to achieve an objective evaluation and rapid tuning of the anti-sway control algorithm.

[0019] For control, TCP / IP communication with the host computer is used. Servo motor 21 and infrared sensor 8 are both slave devices, connected to the host computer via a PLC. The host computer outputs a trajectory in the form of a position sequence to drive the servo drive, thereby causing the elastic structure to complete lifting and lowering motion along the Z-axis. By acquiring data from the sensors, the end effector jitter index is obtained, and the anti-sway control effects of different schemes are compared.

Claims

1. An experimental platform for anti-sway motion control of an elastic structure, characterized in that, It includes a bracket, a servo drive system, an elastic structure, a lead screw (4), a lead screw nut (5), a slider (6), a guide rail (7), a laser displacement sensor (8), a long rod (9), and a host computer; The support frame provides support for other components of the entire experimental platform, including the lower frame and the upper vertical plate; The servo drive system is used to apply excitation motion according to the planned trajectory, including a servo motor (21) and a servo driver (22) fixed in the lower frame; the servo motor (21) and the servo driver (22) are electrically connected; the output shaft of the servo motor (21) is fixedly connected to the lead screw (4); The guide rail (7) is vertically fixed on both sides of the upper vertical plate in the bracket; the slider (6) is installed on the guide rail (7) and moves up and down along the guide rail (7) as the lead screw (4) rotates. The lead screw (4) is arranged vertically between two guide rails (7); The elastic structure includes a flexible beam (31), a horizontal plate, and a clamping mounting base (32). The two ends of the horizontal plate are fixed to two sliders (6) on the guide rail (7) by the clamping mounting base (32), and the middle part of the horizontal plate is fixed to the lead screw nut (5). The flexible beam (31) is set perpendicular to the horizontal plate, and its plane remains horizontal when it is static. The flexible beam (31) is used to generate an elastic response under excitation. The laser displacement sensor (8) is located on the lower side of the end of the flexible beam (31) and is fixed to the bracket by a long rod (9); The host computer is connected to the servo driver (22) and the laser displacement sensor (8) respectively, and collects information from both. The end jitter characteristics are obtained based on the collected information.

2. The elastic structure anti-sway motion control experimental platform according to claim 1, characterized in that, The lower frame of the bracket is constructed from the upper and lower bases and the supporting frame (12) between the upper and lower bases, and the upper vertical plate is vertically fixed to the upper base.

3. The elastic structure anti-sway motion control experimental platform according to claim 1, characterized in that, The servo driver (22) is fixed to the lower base, and the servo motor (21) is fixed to the upper base.

4. The elastic structure anti-sway motion control experimental platform according to claim 1, characterized in that, The reinforcing plate is arranged in a triangle between the cross plate and the end of the flexible beam (31) near the lead screw.

5. The elastic structure anti-sway motion control experimental platform according to claim 1, characterized in that, The host computer software system is set up in the upper part, including a trajectory planning module and a data acquisition and processing module. The trajectory planning module outputs the position sequence and sends it to the servo drive system; the data acquisition and processing module is used to acquire the signal detected by the laser displacement sensor (8) and process the data in the host computer.

6. A method for detecting end-effector jitter, implemented using an elastic structure anti-sway motion control experimental platform as described in any one of claims 1-5, characterized in that, The specific steps are as follows: Step 1: The host computer outputs the trajectory in the form of a position sequence and drives the servo motor (21) to apply excitation; Step 2: The servo motor (21) rotates, driving the lead screw (4) to rotate. The lead screw nut (5) drives the elastic structure to move vertically along the guide rail (7) according to the trajectory output by the host computer. Step 3: The laser displacement sensor (8) aligns with the end of the flexible beam (31) and collects displacement data; Step 4: The laser displacement sensor (8) uploads the collected displacement data to the host computer and outputs the displacement data of the end of the flexible beam (31); Step 5: Calculate the end jitter index based on the displacement data and output the evaluation results.

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