Synchronous deviation elimination method for double-swing-arm mechanism of wind tunnel

Abstract

The invention discloses a wind tunnel double-swing-arm mechanism synchronous deviation elimination method, which comprises the steps of synchronous motion preparation, synchronous deviation elimination motion, synchronous motion positioning and the like, and is characterized in that a motion shaft enters a position closed-loop and synchronous control mode through enabling and starting synchronization of synchronous motion preparation; through the synchronous deviation elimination motion process, elimination motion parameter setting is completed, a master shaft and a slave shaft are moved to set synchronous positions respectively, the master shaft and the slave shaft enter a synchronous coupling state, therefore, synchronous deviation generated in the motion shaft enabling process is eliminated, and then the function of unbiased synchronous motion between the master motion shaft and the slave motion shaft is achieved through normal motion positioning. According to the invention, the existing motion control parameters and motion control flow are not changed, and the motion process is not influenced.

Description

Technical Field

[0001] The present invention relates to the field of wind tunnel tests, and particularly to a method for eliminating synchronous deviation of a wind tunnel double swing arm mechanism. Background Art

[0002] The wind tunnel double swing arm mechanism drives the middle support rod and the test model to perform angular motion through the rigid connection between the swing arm mechanisms on both sides. Its mechanism composition and motion direction are as shown in Figure 1 and Figure 2 To ensure the accuracy of angle-of-attack positioning and the continuity of angle-of-attack changes, and to avoid generating roll angles, it should be ensured that the angular positions of the swing arm mechanisms on both sides are as consistent as possible and move synchronously. Generally speaking, the structural transmission parameters of the swing arm mechanisms on both sides are the same, and it is relatively easy to achieve synchronous control during the motion process. However, during the motion preparation process such as start enabling, due to problems such as structural coupling, mechanism clearance, and structural parameter matching, the mechanism is prone to a small amount of deviation during the motor brake release process, resulting in a double-axis synchronous deviation. This deviation will not be eliminated automatically and accumulates with the increase in the number of enabling operations. Therefore, measures must be taken to eliminate the generated synchronous deviation.

[0003] The prior art can effectively reduce the synchronous deviation generated by a single enabling operation by adjusting the adjustment parameters, but it cannot solve the problem of deviation accumulation. After multiple switch enabling operations, a large deviation amount will still accumulate, and the changed adjustment parameters affect the continuity of the change in motion speed, bringing an adverse impact on the motion control process. Using the method of adjusting the position of the unilateral swing arm mechanism to eliminate the deviation can only eliminate the current deviation, and new displacement deviations will still be generated due to the re-enabling operation caused by the control mode switch. Summary of the Invention

[0004] The purpose of the present invention is to design a method for eliminating synchronous deviation on the basis of the prior art to ensure the elimination of synchronous deviation without changing the existing motion control parameters and motion control process.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A method for eliminating synchronous deviation of a wind tunnel double swing arm mechanism includes the following steps: Step 1: Set the absolute value of the relative motion amount corresponding to the synchronous position of the two axes, and set the absolute value of the relative motion amount corresponding to the target position of the motion; Step 2: On the basis of Step 1, determine that the synchronous coupling position can be entered before reaching the target position during the synchronous deviation elimination motion process; Step 3: Enable each motion axis. After the angle value is stable, based on the magnitude relationship of the current positions of the master and slave axes, complete the determination of the deviation elimination motion direction and the setting of the relative motion amount; Step 4: Input the motion parameters for deviation elimination, and complete the calculation of the dual-axis synchronous position and target position for deviation elimination motion; Step 5: According to the relative motion amount required for the set error elimination motion synchronous angle and target angle, complete the setting of the acceleration and acceleration / deceleration time during the master-slave axis error elimination motion; Step 6: Start the error elimination motion of the master-slave axis. The master-slave axis reaches the set synchronous position according to the motion relationship respectively, the dual axes enter the synchronous coupling state, and synchronously move to the set target angle to complete the synchronous deviation elimination process.

[0006] In the above technical solution, the set dual-axis target position for deviation elimination motion is the same position. After completing the synchronous deviation elimination motion, the position deviation between the dual axes will be close to 0°.

[0007] In the above technical solution, the absolute value of the motion amount corresponding to the synchronous position is less than the absolute value of the relative motion amount corresponding to the target position.

[0008] In the above technical solution, in Step 3, the determination rule is: When the main axis angle is greater than the slave axis angle, the deviation elimination motion direction is positive, and the relative angular motion amount involved in the dual-axis synchronous position and target position of the deviation elimination motion is positive; When the main axis angle is less than the slave axis angle, the deviation elimination motion direction is negative, and the relative angular motion amount involved in the dual-axis synchronous position and target position of the deviation elimination motion is negative.

[0009] In the above technical solution, the expression for the dual-axis synchronous position or target position of the deviation elimination motion is: , Where: is the angle value of the deviation elimination motion, is the relative motion amount of the deviation elimination motion, is the main axis angle position at enabling. When the subscript value n is 1, it represents the synchronous angle value, and when it is 2, it represents the target angle value.

[0010] In the above technical solution, the motion relationship expression for the deviation elimination motion of the main axis and the slave axis is:

[0011] Where: is the relative motion amount of the deviation elimination motion synchronous position, is the main axis angular acceleration, is the time for the master-slave axis to reach the synchronous angle, is the speed of the main axis when it reaches the synchronous angle, is the angle value of the deviation elimination motion, is the slave axis angle position at enabling, The angular acceleration of the slave axis The maximum speed reached by the slave axis The time for the slave axis to reach the maximum speed

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: It can achieve that the dual-axis target positions of the deviation elimination motion setting are the same position, and the position deviation between the two axes will be close to 0 after the synchronous deviation elimination motion; It can achieve that both the synchronous position and the target position of the dual-axis synchronous deviation elimination motion setting only need to superimpose a very small offset (less than the positioning accuracy requirement value) on the basis of the angle at the time of enabling, and can meet the requirement that the angular displacement generated during the elimination process is as small as possible; It can achieve that both the synchronous position and the target position of the dual-axis synchronous deviation elimination motion setting are superimposed and set on the basis of the current angle, meeting the deviation elimination requirements at any angle point; It can achieve that the synchronous deviation elimination motion dynamically determines the direction of the error elimination motion according to the current dual-axis deviation situation, and can meet the elimination requirements for different deviation values and deviation directions; It can achieve that each synchronous enabling operation will execute the dual-axis deviation elimination process again, and there will be no situation of deviation accumulation; It can achieve that without changing the existing motion control parameters and motion control process, it has no impact on the motion process itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be described by way of examples with reference to the accompanying drawings, where: Figure 1 It is a schematic diagram of the side view of the mechanism and the change of the angle of attack; Figure 2 It is a schematic diagram of the composition and motion of the double swing arm mechanism; Figure 3 It is a flow chart of synchronous deviation elimination; Figure 4 It is a graph showing the relationship between the speeds of the two axes over time during the error elimination motion process; Figure 5 It is a schematic diagram of the dual-axis synchronous deviation of the existing method for enabling synchronous operation of a certain mechanism; Figure 6 It is a schematic diagram of the dual-axis synchronous deviation of this embodiment; In the figure: 1 is the drive motor, 2 is the reducer, 3 is the change of the angle of attack, 4 is the strut mechanism, 5 is the rotation center, and 6 is the test model. DETAILED DESCRIPTION OF THE INVENTION

[0014] All features disclosed in this specification, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any manner.

[0015] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) can be replaced by other equivalent or similar-purpose alternative features unless specifically stated. That is, unless specifically stated, each feature is only an example of a series of equivalent or similar features.

[0016] The mechanism targeted in this embodiment is as Figure 1 and Figure 2 the structure shown, specifically including a drive motor 1, a speed reducer 2, a strut mechanism 4, and a test model 6; the output shaft of the drive motor 1 is the rotation center 5, and the test model 6 has an angle of attack change 3 under the drive of the strut mechanism 4.

[0017] The solution of this embodiment is as Figure 3 shown, including steps such as synchronous motion preparation, synchronous deviation elimination motion (including biaxial deviation calculation, motion direction determination, target / synchronous position setting, motion parameter calculation and setting, motion positioning, entering synchronous coupling), and synchronous motion positioning. Through the enabling of synchronous motion preparation and the start of synchronization, the motion axes enter the position closed-loop and synchronous control modes. On this basis, through the synchronous deviation elimination motion process, the motion parameter settings are completed, and the master and slave axes are respectively moved to the set synchronous positions, enabling the master and slave axes to enter the synchronous coupling state, thereby eliminating the synchronous deviation generated during the enabling process of the motion axes. Then, through normal motion positioning, the function of deviation-free synchronous motion between the master and slave motion axes is achieved; specifically: In the mechanism control software, complete the setting of the absolute value of the relative motion amount corresponding to the biaxial synchronous position and the motion target position related to the synchronous deviation elimination motion. Let the absolute value of the relative motion amount of the synchronous position be , and the absolute value of the relative motion amount of the target position be , ensuring that is satisfied to ensure that the synchronous coupling position can be entered before reaching the target position during the error elimination motion process. Click the preparation button on the software main interface, and the system starts the motion synchronization control preparation.

[0018] The system enables each motion axis and starts the synchronization function. After the angle value is stable, the system completes the determination of the error elimination motion direction and the setting of the relative motion amount according to the current position size relationship of the master and slave axes of the swing arm mechanism. The determination criterion is specifically based on the magnitudes of the main axis angle and the slave axis angle, thereby establishing the motion relationship of the error elimination motion.

[0019] The set parameters of this embodiment are: is the main axis angle position at enabling, is the slave axis angle position at enabling, is the angle value of the error elimination motion, is the relative motion amount of the error elimination motion, is the spindle angular acceleration, is the slave axis angular acceleration, is the time for the master and slave axes to reach the synchronous angle, is the speed of the spindle when it reaches the synchronous angle, is the angular value of the deviation elimination movement, is the slave axis angular acceleration, is the maximum speed reached by the slave axis, is the time for the slave axis to reach the maximum speed. When the subscript value of n is 1, it represents the synchronous angle value, and when it is 2, it represents the target angle value; Therefore, is the two-axis synchronous position (in °) of the deviation elimination movement, is the target position (in °) of the deviation elimination movement, is the relative angular movement amount (in °) of the two-axis synchronous position of the deviation elimination movement, is the relative angular movement amount (in °) of the target position of the deviation elimination movement.

[0020] When , the direction of the deviation elimination movement is positive, and the relative angular movement amounts and the target position involved in the two-axis synchronous position , are positive; When , the direction of the deviation elimination movement is negative, and the relative angular movement amounts and the target position involved in the two-axis synchronous position , are negative; The system calculates the two-axis synchronous position and the target position of the deviation elimination movement according to the input deviation elimination movement parameters. The calculation relationship is shown in the formula: .

[0021] The system sets the relevant accelerations and acceleration / deceleration times during the deviation elimination movement of the master and slave axes according to the required relative movement amount of the set deviation elimination movement synchronous angle and the target angle according to the planned movement relationship.

[0022] In this embodiment, taking the spindle angle being greater than the slave axis angle as an example, the relationship between the speed and time of the motion curve is shown in Figure 4 .

[0023] The motion trajectory is as follows:

[0024] Among them, 、 、 、 Based on the system set values as known parameters, calculate 、 、 、 、 the value of, as Figure 4 shown, is the time for the error elimination movement to reach the target position, generally taking .

[0025] Start the error elimination movement of the master and slave axes. The master and slave axes reach the set synchronous positions respectively according to the planned motion relationship , the two axes enter the synchronous coupling state, the positions of the two axes are consistent, and they move synchronously to the set target angle to complete the synchronous deviation elimination process.

[0026] At this time, input the motion target angle at the control end for positioning, and start the deviation-free synchronous motion positioning between the master and slave axes. The results are as Figure 5 , Figure 6 shown, which has obvious effects compared with the prior art.

[0027] The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, as well as any new method or process step or any new combination disclosed.

Claims

1. A method for eliminating synchronization deviation of a double swing arm mechanism in a wind tunnel, characterized in that The following steps are involved: Step 1: Set the absolute value of the relative motion corresponding to the synchronous position of the two axes, and set the absolute value of the relative motion corresponding to the target position of the motion; Step 2: Based on step 1, determine whether the synchronous coupling position can be entered before reaching the target position during the synchronous deviation elimination movement; Step 3: Enable each motion axis, and after the angle value stabilizes, determine the motion direction of deviation elimination and set the relative motion amount according to the current position size relationship of the master and slave axes; Step 4: Input the deviation elimination motion parameters to complete the calculation of the deviation elimination motion dual-axis synchronous position and target position; Step 5: According to the set error elimination motion synchronization angle and the relative motion amount required by the target angle, complete the setting of the acceleration and acceleration / deceleration time during the error elimination motion of the master and slave axes; Step 6: Start the error elimination motion of the master and slave axes. The master and slave axes reach the set synchronous positions according to the motion relationship respectively. The two axes enter the synchronous coupling state and move synchronously to the set target angle to complete the synchronous deviation elimination process.

2. A method for eliminating synchronization deviation of a wind tunnel double swing arm mechanism according to claim 1, characterized in that: The dual-axis target positions set by the deviation elimination movement are the same position, and the position deviation between the dual axes will be close to 0° after the synchronous deviation elimination movement is completed.

3. The method for eliminating synchronization deviation of a wind tunnel double swing arm mechanism according to claim 1, characterized in that: The absolute value of the movement amount corresponding to the synchronization position is smaller than the absolute value of the relative movement amount corresponding to the target position.

4. A method for eliminating synchronization deviation of a wind tunnel double swing arm mechanism according to claim 1, characterized in that: In step three, the judgment rule is: When the main axis angle is greater than the slave axis angle, the deviation elimination motion direction is positive, and the relative angular motion amount involved in the dual-axis synchronous position and the target position of the deviation elimination motion is positive; When the main axis angle is smaller than the slave axis angle, the deviation elimination motion direction is negative, and the relative angular motion amount involved in the dual-axis synchronous position and the target position of the deviation elimination motion is negative.

5. A method for eliminating synchronization deviation of a wind tunnel double swing arm mechanism according to claim 4, characterized in that: The expression of the dual-axis synchronous position or target position of the deviation elimination motion is: , in: is the angular value of the deviation elimination motion, The relative motion for the deviation elimination motion, The spindle angle position when enabled. When n is the subscript value, it indicates the synchronous angle value when it is 1, and it indicates the target angle value when it is 2.

6. A method for eliminating synchronization deviation of a wind tunnel double swing arm mechanism according to claim 4 or 5, characterized in that: The kinematic relationship expression of the deviation elimination motion between the main axis and the slave axis is: ， in: The relative movement of the synchronous position for deviation elimination motion, is the angular acceleration of the main axis, The time it takes for the master and slave axes to reach the synchronization angle. is the speed when the spindle reaches the synchronous angle, is the angle value of the deviation elimination motion, To enable the slave axis angle position, is the angular acceleration of the slave axis, is the maximum speed reached by the slave axis, is the time for the slave axis to reach maximum speed.

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