A multi-target fiber-optic spectroscopic telescope fiber operation anti-collision operation planning method

Abstract

The present application relates to a kind of multi-target fiber spectrum astronomical telescope fiber operation anti-collision operation planning method, belong to the motion control field of multi-target fiber spectrum astronomical telescope upper fiber receiving positioning robot.The present application first according to the structure of fiber positioning unit, the operation flow of fiber positioning unit is planned;According to the planned operation flow, the interference region scanned by fiber positioning unit is predicted;By detecting whether the interference region of each fiber positioning unit overlaps, all the fiber positioning units that can collide with other units are screened out;The number and number of the fiber positioning units that need to be processed least to prevent collision are calculated using the greedy algorithm;Finally, the new operation target point that can make the fiber positioning unit to be processed avoid collision is obtained by the way of cyclic detection for each fiber positioning unit, instead of the original target point, 99.9% of collision is completely avoided, and the average proportion of observation targets discarded to avoid collision is reduced from the original 25% to 12%.

Description

Technical Field

[0001] This invention belongs to the field of motion control of fiber optic receiver positioning robots on multi-object fiber optic spectroscopic telescopes, specifically involving a collision avoidance operation planning method for the operation of thousands of small-sized, high-density robot clusters. Background Technology

[0002] The Fiber Optic Spectroscopic Survey Telescope (Fiber Spectroscopic Survey Telescope) is a specialized astronomical telescope that employs parallel, partitioned, and controllable methods to simultaneously observe multiple celestial targets. Its focal plane contains multiple movable robots (hereinafter referred to as "fiber positioning units"), each tracking its assigned observation target, as shown in the attached diagram. Figure 11 As shown. To achieve full coverage of the tracking range, various survey telescope structures result in some overlap in the activity range of adjacent fiber optic positioning units. Therefore, when fiber optic positioning units move synchronously, there is a significant possibility of collisions between them. Since collisions greatly affect the motion accuracy of the fiber optic positioning units, thereby affecting the observation accuracy, various survey telescopes employ certain anti-collision strategies to ensure observation accuracy.

[0003] The fiber optic positioning unit of the domestic LAMOST telescope adopts a dual-rotation structure. Each fiber optic positioning unit consists of two rotation axes (central axis and eccentric axis) controlling two components of equal arm length to perform rotational motion. This drives the optical fiber to track celestial targets within a fixed circular range centered on its origin. (See attached diagram.) Figure 3 As shown in the attached diagram. To ensure that there are no blind spots in the movement position of the fiber optic positioning units during observation, the design incorporates up to 58% overlap between the operating area of ​​each fiber optic positioning unit and adjacent fiber optic positioning units. Figure 4 As shown. Currently, the commonly used artificial potential field method can only solve collision avoidance problems when the overlapping area is small. Faced with the large overlapping of the motion areas caused by the simultaneous movement of nearly 4000 fiber optic positioning units like those on LAMOST, solving for the motion path of each fiber optic positioning unit will result in a deadlock, or only some fiber optic positioning units will have a workable path, while the motion paths of the remaining fiber optic positioning units will oscillate and swing within the possible area. Therefore, it is not suitable for the existing LAMOST telescope system. In addition, there are internationally recognized collision avoidance strategies that employ precise solutions for the motion of fiber optic positioning units, i.e., calculating the workable path of each fiber optic positioning unit one by one. However, this method is not only computationally complex, but also difficult to precisely control the motion process due to the slight differences in the motors of each fiber optic positioning unit and the fact that the fiber optic positioning units of LAMOST do not start moving simultaneously.

[0004] Previously, LAMOST employed an open-loop anti-collision strategy to address the element collision problem. This strategy required each fiber optic positioning unit to return to its origin before starting tracking, and then calculate the area each unit needed to scan when moving to the target. If an overlap was detected between the scanned area of ​​a fiber optic positioning unit and other units, that unit's target was abandoned, and it remained at its origin. While this method completely avoided collisions, it required discarding a large number of targets, and each time the target position changed, the fiber optic positioning units needed to return to their origin and be replanned, making the method highly inefficient. Furthermore, the open-loop control method could not monitor the last position of each fiber optic positioning unit, making it impossible to correct errors and leading to error accumulation. Therefore, after the LAMOST observation system underwent a closed-loop modification, the original anti-collision strategy is no longer applicable. Thus, a computationally efficient, real-time planning, collision-avoiding, and target-discarding anti-collision strategy is needed to improve the overall observation efficiency and accuracy of the system. Summary of the Invention

[0005] In order to accurately predict the occurrence of collisions and, while minimizing the observation targets that are abandoned in order to avoid collisions, to plan and completely avoid collisions in real time, this invention provides a collision avoidance operation planning method for the operation of fiber optics in a multi-object fiber optic spectroscopic telescope.

[0006] This invention predicts and plans the entire process of a fiber optic positioning unit from its starting point to its target point in advance, saving the tedious process of multiple discretization checks and greatly improving the efficiency of the fiber optic positioning unit. For fiber optic positioning units that are predicted to potentially collide, collisions are avoided by discarding the original observation target and designating a safe target (i.e., a moving target that has no observation value but will not collide). A greedy algorithm is used to reduce the number of discarded observation targets to improve observation efficiency.

[0007] A collision-avoidance operation planning method for the operation of a multi-object fiber optic spectroscopic astronomical telescope, wherein the astronomical telescope is a fiber optic spectroscopic survey telescope, and more than one hundred movable robots are evenly distributed on its focal plane, wherein the movable robots are fiber optic positioning units.

[0008] The fiber optic positioning unit is circular, with its center being a central axis 1. A central arm and an eccentric arm are connected sequentially along the radius. The lengths of the central arm and the eccentric arm are equal. One end of the central arm is coaxial with the central axis 1. The connection end between the central arm and the eccentric arm is a coaxial eccentric axis 2. The outer end of the eccentric arm is the fiber optic end.

[0009] The motion area of ​​the fiber optic positioning unit is divided into an inner circle where the central arm rotates with the central axis 1 and an outer circle where the eccentric axis 2 rotates with the eccentric arm, forming a double rotation structure. The fiber optic cable for observing celestial targets is located at the end of the eccentric arm.

[0010] The distance between the central axes 1 of adjacent fiber optic positioning units is greater than three times the arm length of the central arm, and the outer rings of adjacent fiber optic positioning units overlap.

[0011] Each fiber optic positioning unit is adjacent to three to six fiber optic positioning units;

[0012] The steps for collision avoidance operation planning are as follows:

[0013] (1) Planning the operation of the fiber optic positioning unit

[0014] The operation of the fiber optic positioning unit is planned in three steps:

[0015] (1.1) The eccentric arm is rotated by the eccentric shaft 2, and the eccentric arm is completely retracted into the inner circle range;

[0016] (1.2) The central arm and the eccentric arm rotate together driven by the central axis 1 until the distance between the position of the celestial target and the eccentric axis is equal to the length of the eccentric arm;

[0017] (1.3) The eccentric arm is rotated by the eccentric shaft 2, and the optical fiber at the outer end of the eccentric arm is rotated to the position of the celestial target.

[0018] (2) Draw the interference region

[0019] According to the three steps of the operation of the fiber optic positioning unit as planned in step (1), and combined with the structure and external dimensions of the central arm and the eccentric arm, draw the area that the central arm and the eccentric arm of each fiber optic positioning unit need to pass through from the starting position to the target celestial body position, that is, determine the complex pattern of the interference region of each fiber optic positioning unit, and obtain more than one hundred complex patterns in total; the complex pattern of each fiber optic positioning unit is called the interference region.

[0020] (3) Overlap detection of collision units

[0021] Overlap detection is performed on the interference regions of all fiber optic positioning units. If the interference regions of two adjacent fiber optic positioning units overlap, it means that the areas traversed by these two fiber optic positioning units when they move to their respective target positions overlap, that is, there is a risk of collision between these two fiber optic positioning units. The active one is the main collision unit, and the passive one is the collision-bearing unit.

[0022] The number of collided units adjacent to the main collision unit is one to six, and the collided units adjacent to the main collision unit are recorded as a set of collided units.

[0023] (4) Screening fiber optic positioning units that undergo anti-collision processing

[0024] A greedy selection algorithm is used to select a portion of the main collision units that must be processed from the main collision units that will collide. The selected main collision units are called the processed units. By planning these processed units, collision avoidance for all fiber optic positioning units is completed.

[0025] (5) Collision avoidance is performed on the selected processing units.

[0026] For the first and second record sets in step (4), collision avoidance is achieved by changing the operating target of the processed unit. A cyclic detection method is adopted to determine the operating target point that can prevent the processed unit from collision, which is then used to replace the original celestial target to achieve collision avoidance.

[0027] The further defined technical solution is as follows:

[0028] In step (1), the rotation angle of the central shaft 1 driving the central arm is 0° to 360°, and the rotation angle of the eccentric shaft 2 driving the eccentric arm is 0° to 180°.

[0029] In step (1), the distance between the central axes 1 of adjacent fiber positioning units is 3.1 times the length of the central arm.

[0030] In step (1.1), the angle between the retracted eccentric arm and the central arm is no greater than 60°.

[0031] In step (4), the specific steps are as follows:

[0032] (4.1) Traverse all the main collision units, calculate and determine the number of collision units contained in the collision unit set of each main collision unit, filter out the main collision unit with the most collision units, set it as a processed unit, record it as the first record set, and delete this processed unit.

[0033] (4.2) Traverse the remaining main collision units, check whether the set of collided units corresponding to each main collision unit contains the processed units selected in step (4.1), remove the main collision units that have been collided from each set of collided units, and then check the number of collided units in each set of collided units, which is recorded as the second record set.

[0034] (4.3) If there is a set of collision units in the second record set with a number of collision units that is not zero, then repeat steps (4.1) and (4.2); if all collision unit sets in the second record set contain zero collision units, then it means that there is no collision risk for the remaining fiber optic positioning units.

[0035] In step (4.3), when repeating step (4.1), each time a new primary collision unit is selected, the contents previously recorded in the first record set are retained, and the new primary collision unit is added to the first record set.

[0036] In step (4.3), when repeating step (4.2), after each re-detection of the number of collided units contained in the collided unit set, the previously recorded content in the second record set is deleted, and the new detection result is used to replace the previous detection result. In step (5), the specific steps are as follows:

[0037] (5.1) Rotate the unit to be processed 15° clockwise from its current position, and then redraw the complex graphic of the interference region in step (2) and perform overlap detection of the interference region in step (3);

[0038] (5.2) If the result of the interference region overlap detection is that the interference region of the processed unit does not overlap with the interference region of other fiber optic positioning units, then the position of the processed unit after rotating 15° clockwise is used to replace the original celestial target position of the processed unit, thus completing the collision avoidance of the processed unit.

[0039] (5.3) If the result of the interference region overlap detection is that the interference region of the processed unit overlaps with the interference region of other fiber optic positioning units and the rotation angle is less than 360°, then repeat step (5.1); if the rotation angle is more than 360°, then the initial rotation angle is offset by 5° from the angle of the 15° clockwise rotation in step (5.1), and then repeat step (5.1) until the interference region of the processed unit does not overlap with the interference region of other fiber optic positioning units, and the position of the processed unit after rotation is used to replace the original celestial target position of the processed unit, and finally the collision avoidance of the processed unit is completed.

[0040] The beneficial technical effects of this invention are reflected in the following aspects:

[0041] 1. This invention specifies an operating mode for the fiber optic positioning unit. The unit first retracts its eccentric arm to a safe inner circle, then rotates as a whole, and finally extends the eccentric arm to track the observation target. In this fixed operating mode, the interference area swept by the fiber optic positioning unit during operation can be easily predicted. This allows for prediction and planning of the entire process from the starting point to the target point before the unit begins to move. Furthermore, the retraction of the eccentric arm ensures that the fiber optic positioning unit remains within a safe inner circle during its rotation, preventing collisions with other fiber optic positioning units. The risk of collision only arises during the retraction and extension of the eccentric arm, significantly reducing the probability of collisions. This operating mode not only eliminates the need for continuous monitoring and multiple replanning processes during fiber optic operation, simplifying and controlling the process, but also reduces computational complexity and performance requirements for the fiber optic positioning unit's motor. It also reduces the number of fiber optic positioning units that need subsequent collision avoidance processing, thereby reducing the number of observation targets that need to be discarded and effectively improving observation efficiency.

[0042] 2. This invention proposes a method for selecting processing units using a greedy selection algorithm. It selects primary collision units with a large number of potential collision targets as processing units, and achieves collision avoidance for all fiber optic positioning units by applying collision avoidance measures to these processed units. This method avoids applying collision avoidance measures to all fiber optic positioning units identified as potentially colliding. Instead, it selects fiber optic positioning units with a greater impact on collisions based on their collision relationships. While ensuring complete collision avoidance for all fiber optic positioning units, the greedy selection approach minimizes the number of fiber optic positioning units requiring collision avoidance measures. The fewer fiber optic positioning units that require collision avoidance, the fewer observation targets are abandoned. This method effectively reduces the number of observation targets abandoned for collision avoidance, ultimately reducing the proportion of abandoned observation targets from 25% in the original method to 12%.

[0043] 3. The cyclic detection avoidance algorithm proposed in this invention utilizes the structure and distribution of fiber optic positioning units to find safe operating targets by rotating the target point's orientation. It does not require changing the operating mode of the fiber optic positioning units; it only requires redrawing the interference region according to the original operating mode and the new operating target. This not only reduces computational complexity but also achieves a 99.9% success rate in avoiding collisions with fiber optic positioning units. It achieves excellent anti-collision effects with relatively small computational load and improves the system's operating speed.

[0044] 4. The anti-collision operation planning method of the present invention does not require restrictions on the starting position of each fiber optic positioning unit. Since the present invention plans the process of the fiber optic positioning unit moving from any position to the target position into a fixed three steps, the operation process of the fiber optic positioning unit starting from any position is simple and predictable. When it is necessary to change the observation target, each fiber optic positioning unit does not need to return to the origin and can directly start the movement planning from the current position. Therefore, it can be used in conjunction with the closed-loop detection system of the telescope to fine-tune the position of the fiber optic positioning unit in real time, thereby greatly improving the positioning and tracking accuracy of the fiber optic positioning unit. Attached Figure Description

[0045] Figure 1 This is a real photograph of the LAMOST small focal plane system in Embodiment 1 of the present invention.

[0046] Figure 2 This is a flowchart illustrating the anti-collision strategy for the operation of multi-target fiber optic spectroscopy in an astronomical telescope according to an embodiment of the present invention.

[0047] Figure 3 This is a schematic diagram of the fiber optic positioning unit structure in an embodiment of the present invention.

[0048] Figure 4 This is a schematic diagram of the positional relationship between adjacent fiber optic positioning units in an embodiment of the present invention. The asterisks represent the observed celestial targets. Region (1) is the overlapping area of ​​the movement range of the three fiber optic positioning units. Regions (2), (3), and (4) are the overlapping areas of the movement ranges of fiber optic positioning units ① and ②, ② and ③, and ③ and ①, respectively.

[0049] Figure 5 This is a schematic diagram of the first step in the operation process of the fiber optic positioning unit in an embodiment of the present invention.

[0050] Figure 6 This is a schematic diagram of the second step of the operation process of the fiber optic positioning unit in an embodiment of the present invention.

[0051] Figure 7 This is a schematic diagram of the third step of the operation process of the fiber optic positioning unit in an embodiment of the present invention.

[0052] Figure 8 This is a schematic diagram of the interference region of the fiber optic positioning unit in an embodiment of the present invention. The area within the thick solid line is the interference region.

[0053] Figure 9 This is a schematic diagram of the interference region of 276 fiber optic positioning units displayed by the software in Embodiment 1 of the present invention.

[0054] Figure 10 yes Figure 9 A magnified view of a portion of the image.

[0055] Figure 11This is a real photograph of the LAMOST focal plane system in Embodiment 2 of the present invention.

[0056] Figure 12 This is a schematic diagram of the interference region of 3085 units displayed by the software in Embodiment 2 of the present invention.

[0057] Figure 13 yes Figure 12 A magnified view of a portion of the image. Detailed Implementation

[0058] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0059] Example 1

[0060] The astronomical telescope in this embodiment 1 is a multi-object fiber optic spectroscopic survey telescope. See [link to example]. Figure 1 The focal plane is evenly distributed with 276 robots capable of two-dimensional rotational movement, which are fiber optic positioning units.

[0061] The fiber optic positioning unit is circular, with its center being the central axis 1. A central arm and an eccentric arm are connected sequentially along the radius. The lengths of the central arm and the eccentric arm are equal. One end of the central arm is coaxial with the central axis 1. The connection end between the central arm and the eccentric arm is the coaxial eccentric axis 2. The outer end of the eccentric arm is the fiber optic end.

[0062] The eccentric arm width, central axis arm width, and center distance of each unit of the fiber optic positioning unit have been obtained through measurement and are used as known quantities for collision detection and collision avoidance planning.

[0063] The motion area of ​​the fiber optic positioning unit is divided into an inner circle where the central arm rotates with the central axis 1 and an outer circle where the eccentric axis 2 rotates with the eccentric arm, forming a double rotation structure. The fiber optic cable for observing celestial targets is located at the end of the eccentric arm.

[0064] The distance between the central axes 1 of adjacent fiber optic positioning units is greater than three times the arm length of the central arm, and the outer rings of adjacent fiber optic positioning units overlap.

[0065] Each fiber optic positioning unit is adjacent to three to six fiber optic positioning units.

[0066] See Figure 2 The specific operation steps of the anti-collision strategy for the fiber positioning unit of this multi-object fiber optic spectroscopic telescope are as follows:

[0067] (1) Planning the operation of the fiber optic positioning unit

[0068] The operation of the fiber optic positioning unit is planned in three steps:

[0069] (1.1) The eccentric arm is rotated by the eccentric shaft 2, and the eccentric arm is completely retracted into the inner circle range;

[0070] (1.2) The central arm and the eccentric arm rotate together driven by the central axis 1 until the distance between the position of the celestial target and the eccentric axis is equal to the length of the eccentric arm;

[0071] (1.3) The eccentric arm is rotated by the eccentric shaft 2, and the optical fiber at the outer end of the eccentric arm is rotated to the position of the celestial target.

[0072] See Figure 3 In this embodiment 1, each fiber optic positioning unit is as follows: Figure 3 The double-rotating structure shown has a central axis 1 at its center, with a rotation angle range of 0° to 360°. Along the radius are a central arm and an eccentric arm connected sequentially, with the lengths of the central arm and the eccentric arm being equal. The connecting end of the central arm and the eccentric arm is an eccentric shaft 2, with a rotation angle range of 0° to 180°. The outer end of the eccentric arm is the fiber optic tip. (See also...) Figure 4 The length of the central arm and the eccentric arm of each fiber optic positioning unit is 8.25 mm. The distance between the central axes of adjacent units is 25.6 mm, which is more than three times the arm length. The movement area of ​​the fiber optic positioning unit is divided into an inner circle with the central arm length as the radius and an outer circle outside the central arm range. The inner circles of each fiber optic positioning unit do not overlap and belong to the safe area, while the outer circle has a large area of ​​overlap. Among them, area (1) is the overlapping area of ​​the movement range of the three fiber optic positioning units. Areas (2), (3), and (4) are the overlapping areas of the movement range of fiber optic positioning units ① and ②, ② and ③, and ③ and ①, respectively. When the fiber optic positioning unit moves in the overlapping area, there is a great risk of collision with the adjacent fiber optic positioning unit.

[0073] To reduce the workload of predicting the motion interference range and decrease the probability of overlapping interference ranges among the fiber optic positioning units, the three-step plan for the operation of the fiber optic positioning units is detailed below:

[0074] (1.1) See Figure 5 The eccentric arm is rotated by the eccentric shaft 2, and the eccentric arm is brought back to a state where the angle between it and the central arm is 60°, so that the eccentric arm is completely within the inner circle.

[0075] (1.2) See Figure 6 The central arm and the eccentric arm rotate together, driven by the central axis 1, until the distance between the celestial target position and the eccentric axis 2 is equal to the length of the eccentric arm. Since the eccentric arm has been retracted to the inner circle in step (1.1), there is no risk of the fiber optic positioning unit colliding with other fiber optic positioning units during this step.

[0076] (1.3) See also Figure 7The central axis 1 stops rotating, and the eccentric arm is rotated by the eccentric axis 2, which moves the optical fiber at the outer end of the eccentric arm to the position of the celestial target.

[0077] See Figure 8 Based on the areas swept by the fiber optic positioning unit in steps (1.1), (1.2), and (1.3), the interference region of the fiber optic positioning unit is plotted, as follows: Figure 8 The area inside the medium-thick solid line.

[0078] (2) Draw the interference region

[0079] According to the three steps of the operation of the fiber optic positioning unit as planned in step (1), and in combination with the structure and external dimensions of the central arm and the eccentric arm, draw the area that the central arm and the eccentric arm of each fiber optic positioning unit need to pass through from the starting position to the target celestial body position, that is, determine the complex diagram of the interference region of each fiber optic positioning unit.

[0080] See Figure 9 The interference region of 276 fiber optic positioning units yielded a total of 276 complex patterns.

[0081] (3) Overlap detection of collision units

[0082] Overlap detection is performed on the interference regions of all fiber optic positioning units. If the interference regions of two adjacent fiber optic positioning units overlap, it means that the areas traversed by these two fiber optic positioning units when they move to their respective target positions overlap, that is, there is a risk of collision between these two fiber optic positioning units. The active one is the main collision unit, and the passive one is the collision-bearing unit.

[0083] The number of collided units adjacent to the main collision unit is one to six, and the collided units adjacent to the main collision unit are recorded as a set of collided units.

[0084] See Figure 10 , Figure 10 Fiber optic positioning units exhibiting overlapping interference regions within regions I, II, III, and IV of the central system. The system will sequentially check whether the interference regions of each fiber optic positioning unit overlap with those of all its neighboring fiber optic positioning units. If overlapping regions exist, such as... Figure 10 The fiber optic positioning units in regions I, II, III, and IV represent units that may collide with other fiber optic positioning units. Figure 10In region I, cell A needs to be recorded as the primary collision cell, and surrounding cells B that may collide with it need to be recorded in the set of collided cells of cell A. If there is no overlapping area, it means that the fiber optic positioning cell has no possibility of collision and can operate normally to the celestial target position to complete the normal observation task without processing. After traversing all fiber optic positioning cells, 12 primary collision cells were successfully detected, and the set of collided cells corresponding to each primary collision cell was successfully recorded.

[0085] (4) Screening fiber optic positioning units for collision processing

[0086] A greedy selection algorithm is used to filter out a subset of primary collision units that must undergo collision avoidance processing from the primary collision units where collisions are likely to occur. These filtered primary collision units are called the processed units. By planning these processed units, collision avoidance for all fiber optic positioning units is achieved. The specific steps are as follows:

[0087] (4.1) Traverse all the main collision units, calculate and determine the number of collision units contained in the collision unit set of each main collision unit, filter out the main collision unit with the most collision units, set it as a processed unit, record it as the first record set, and delete this processed unit.

[0088] (4.2) Traverse the remaining main collision units, check whether the set of collided units corresponding to each main collision unit contains the processed units selected in step (4.1), remove the main collision units that have been collided from each set of collided units, and then check the number of collided units in each set of collided units, which is recorded as the second record set.

[0089] (4.3) If there is a set of collided units in the second record set with a non-zero number of collided units, repeat steps (4.1) and (4.2). When repeating step (4.1), each time a new primary collided unit is selected, the content previously recorded in the first record set is retained, and the new primary collided unit is added to the first record set. When repeating step (4.2), each time the number of collided units in the collided unit set is re-detected, the content previously recorded in the second record set is deleted, and the new detection result replaces the previous detection result. If the number of collided units in all collided unit sets in the second record set is zero, it means that there is no collision risk for all remaining fiber optic positioning units.

[0090] Through the above operations, 8 units to be processed were successfully selected from 12 main collision units and recorded in the first record set. By planning these 8 units to be processed, collision avoidance for all fiber optic positioning units was completed.

[0091] (5) Collision avoidance is performed on the selected units to be processed.

[0092] For the first and second record sets in step (4), collision avoidance is achieved by changing the operational target of the processed unit. A cyclic detection method is used to determine the operational target point that can prevent the processed unit from colliding, which is then used to replace the original target to complete the avoidance. The specific operation is as follows:

[0093] (5.1) Rotate the unit to be processed 15° clockwise from its current position, and then redraw the complex graphic of the interference region in step (2) and perform overlap detection of the interference region in step (3);

[0094] (5.2) If the result of the interference region overlap detection is that the interference region of the processed unit does not overlap with the interference region of other fiber optic positioning units, then the position of the processed unit after rotating 15° clockwise is used to replace the original celestial target position of the processed unit, thus completing the collision avoidance of the processed unit.

[0095] (5.3) If the result of the interference region overlap detection is that the interference region of the processed unit overlaps with the interference region of other fiber optic positioning units and the rotation angle is less than 360°, then repeat step (5.1); if the rotation angle is more than 360°, then the initial rotation angle is offset by 5° from the angle of the 15° clockwise rotation in step (5.1), and then repeat step (5.1) until the interference region of the processed unit does not overlap with the interference region of other fiber optic positioning units, and the position of the processed unit after rotation is used to replace the original celestial target position of the processed unit, and finally the collision avoidance of the processed unit is completed.

[0096] Through the above process, corresponding replacement target points were successfully found for the 8 processed units to avoid collisions during operation. In the end, the collision was completely avoided at the cost of abandoning 8 of the 276 observation targets.

[0097] Example 2

[0098] The astronomical telescope in this embodiment 2 is a fiber optic spectroscopic survey telescope. See [link to example]. Figure 11 The focal surface is evenly distributed with 3085 robots capable of two-dimensional rotational movement, which are fiber optic positioning units.

[0099] The fiber optic positioning unit is circular, with its center being the central axis 1. A central arm and an eccentric arm are connected sequentially along the radius. The lengths of the central arm and the eccentric arm are equal. One end of the central arm is coaxial with the central axis 1. The connection end between the central arm and the eccentric arm is the coaxial eccentric axis 2. The outer end of the eccentric arm is the fiber optic end.

[0100] The eccentric arm width, central axis arm width, and center distance of each unit of the fiber optic positioning unit have been obtained through measurement and are used as known quantities for collision detection and collision avoidance planning.

[0101] The motion area of ​​the fiber optic positioning unit is divided into an inner circle where the central arm rotates with the central axis 1 and an outer circle where the eccentric axis 2 rotates with the eccentric arm, forming a double rotation structure. The fiber optic cable for observing celestial targets is located at the end of the eccentric arm.

[0102] The distance between the central axes 1 of adjacent fiber optic positioning units is greater than three times the arm length of the central arm, and the outer rings of adjacent fiber optic positioning units overlap.

[0103] Each fiber optic positioning unit is adjacent to three to six fiber optic positioning units. See also Figure 2 The specific operation steps of the anti-collision strategy for the fiber positioning unit of this multi-object fiber optic spectroscopic telescope are as follows:

[0104] (1) Planning the operation of the fiber optic unit

[0105] Step (1) of this embodiment 2 is exactly the same as step (1) of embodiment 1.

[0106] (2) Draw the unit interference region

[0107] According to the three steps of the operation of the fiber optic positioning unit as planned in step (1), and in combination with the structure and external dimensions of the central arm and the eccentric arm, draw the area that the central arm and the eccentric arm of each fiber optic positioning unit need to pass through from the starting position to the target celestial body position, that is, determine the complex diagram of the interference region of each fiber optic positioning unit.

[0108] See Figure 12 The interference region of 3085 fiber optic positioning units can be practically controlled, resulting in 3085 complex patterns.

[0109] (3) Overlap detection of collision units

[0110] The interference regions of all fiber optic positioning units are overlapped. If the interference regions of two adjacent fiber optic positioning units overlap, it means that the areas traversed by these two fiber optic positioning units when they move to their respective target positions overlap, that is, there is a risk of collision between these two fiber optic positioning units. The active one is the main collision unit, and the passive one is the collision-bearing unit.

[0111] The number of collided units adjacent to the main collision unit is one to six, and the collided units adjacent to the main collision unit are recorded as a set of collided units.

[0112] See Figure 13 , Figure 13Region I contains fiber optic positioning units where interference regions overlap. The system will sequentially check whether the interference regions of each fiber optic positioning unit overlap with those of all its neighboring fiber optic positioning units. If overlapping regions exist, such as... Figure 13 The fiber optic positioning units in region I represent units that may collide with other fiber optic positioning units. Figure 13 In region I, cell A needs to be recorded as the primary colliding cell. Cells B and C, which may collide with it, need to be recorded in the set of collided cells of cell A. If there is no overlapping area, it means that the fiber optic positioning cell has no possibility of collision and can operate normally to the celestial target position to complete the normal observation task without further processing. After traversing all fiber optic positioning cells, 699 primary colliding cells were successfully detected, and the set of collided cells corresponding to each primary colliding cell was successfully recorded.

[0113] (4) Screening fiber optic positioning units for collision processing

[0114] A greedy selection algorithm is used to select a portion of the main collision units that must be processed for collision avoidance from the main collision units that will collide. The selected main collision units are called the processed units. By planning these processed units, collision avoidance for all fiber optic positioning units is completed. The specific operation is exactly the same as the specific steps of the greedy selection algorithm in step (4) of embodiment 1.

[0115] By using the same greedy selection algorithm as step (4) in Example 1, 369 processing units were successfully selected from 699 main collision units and recorded in the first record set. By planning these 369 processing units, collision avoidance of all fiber optic positioning units was completed.

[0116] (5) Collision avoidance is performed on the selected units to be processed.

[0117] For the first and second record sets in step (4), collisions are avoided by changing the operating target of the processed unit. A cyclic detection method is adopted to determine the operating target point that can prevent the processed unit from colliding, which is used to replace the original target to complete the avoidance. The specific operation is exactly the same as the specific operation described in step (5) of embodiment 1.

[0118] Through the same cyclic detection operation as step (5) in Example 1, the corresponding replacement target points for 369 processed units were successfully found to avoid collisions during operation. In the end, the collisions were completely avoided at the cost of abandoning 369 of the 3085 observation targets.

[0119] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A collision-avoidance operation planning method for the operation of a multi-object fiber optic spectroscopic astronomical telescope, wherein the telescope is a fiber optic spectroscopic survey telescope, and more than one hundred movable robots are evenly distributed on its focal plane, wherein the movable robots are fiber optic positioning units, characterized in that: The fiber positioning unit is circular, with its center being the central axis (1). A central arm and an eccentric arm are connected sequentially along the radius. The length of the central arm and the length of the eccentric arm are equal. One end of the central arm is coaxial with the central axis (1). The connection end of the central arm and the eccentric arm is a coaxial eccentric axis (2). The outer end of the eccentric arm is the fiber end. The motion area of ​​the fiber optic positioning unit is divided into an inner circle that drives the central arm to rotate with the central axis (1) and an outer circle that drives the eccentric arm to rotate with the eccentric axis (2), forming a double rotation structure, so that the fiber optic for observing celestial targets is located at the fiber end of the eccentric arm. The distance between the central axes (1) of adjacent fiber optic positioning units is greater than three times the arm length of the central arm, and the outer rings of adjacent fiber optic positioning units overlap. Each fiber optic positioning unit is adjacent to three to six fiber optic positioning units; The steps for collision avoidance operation planning are as follows: (1) Planning the operation of the fiber optic positioning unit The operation of the fiber optic positioning unit is planned in three steps: (1.1) The eccentric arm is rotated by the eccentric shaft (2) and the eccentric arm is completely retracted into the inner circle range; (1.2) The central arm and the eccentric arm are driven by the central axis (1) to rotate together until the distance between the position of the celestial target and the eccentric axis is equal to the length of the eccentric arm; (1.3) The eccentric arm is rotated by the eccentric shaft (2) to rotate the optical fiber at the outer end of the eccentric arm to the position of the celestial target; (2) Draw the interference region According to the three steps of the operation of the fiber optic positioning unit as planned in step (1), and combined with the structure and external dimensions of the central arm and the eccentric arm, draw the area that the central arm and the eccentric arm of each fiber optic positioning unit need to pass through from the starting position to the target celestial body position, that is, determine the complex pattern of the interference region of each fiber optic positioning unit, and obtain more than one hundred complex patterns in total; the complex pattern of each fiber optic positioning unit is called the interference region. (3) Overlap detection of collision units Overlap detection is performed on the interference regions of all fiber optic positioning units. If the interference regions of two adjacent fiber optic positioning units overlap, it means that the areas traversed by these two fiber optic positioning units when they move to their respective target positions overlap, that is, there is a risk of collision between these two fiber optic positioning units. The active one is the main collision unit, and the passive one is the collision-bearing unit. The number of collided units adjacent to the main collision unit is one to six, and the collided units adjacent to the main collision unit are recorded as a set of collided units. (4) Screening fiber optic positioning units that undergo anti-collision processing A greedy selection algorithm is used to select a portion of the main collision units that must be processed from the main collision units that will collide. The selected main collision units are called the processed units. By planning these processed units, collision avoidance for all fiber optic positioning units is completed. (5) Collision avoidance is performed on the selected processing units. For the first and second record sets in step (4), collision avoidance is achieved by changing the operating target of the processed unit. A cyclic detection method is adopted to determine the operating target point that can prevent the processed unit from collision, which is then used to replace the original celestial target to achieve collision avoidance.

2. The collision-avoidance operation planning method for the operation of a multi-object fiber optic spectroscopic telescope according to claim 1, characterized in that: In step (1), the rotation angle of the central arm driven by the central shaft (1) is 0° to 360°, and the rotation angle of the eccentric shaft (2) driven by the eccentric arm is 0° to 180°.

3. The collision-avoidance operation planning method for the operation of a multi-object fiber optic spectroscopic telescope according to claim 1, characterized in that: In step (1), the distance between the central axes (1) of adjacent fiber optic positioning units is 3.1 times the length of the central arm.

4. The collision-avoidance operation planning method for the operation of a multi-object fiber optic spectroscopic telescope according to claim 1, characterized in that: In step (1.1), the angle between the retracted eccentric arm and the central arm is no greater than 60°.

5. The anti-collision operation planning method for the operation of a multi-object fiber optic spectroscopic telescope according to claim 1, characterized in that: In step (4), the specific steps are as follows: (4.1) Traverse all the main collision units, calculate and determine the number of collision units contained in the collision unit set of each main collision unit, filter out the main collision unit with the most collision units, set it as a processed unit, record it as the first record set, and delete this processed unit. (4.2) Traverse the remaining main collision units, check whether the set of collided units corresponding to each main collision unit contains the processed units selected in step (4.1), remove the main collision units that have been collided from each set of collided units, and then check the number of collided units in each set of collided units, which is recorded as the second record set. (4.3) If there is a set of collision units in the second record set with a number of collision units that is not zero, then repeat steps (4.1) and (4.2); if all collision unit sets in the second record set contain zero collision units, then it means that there is no collision risk for the remaining fiber optic positioning units.

6. The anti-collision operation planning method for fiber optic operation of a multi-object fiber optic spectroscopic telescope according to claim 5, characterized in that: In step (4.3), when repeating step (4.1), each time a new primary collision unit is selected, the contents previously recorded in the first record set are retained, and the new primary collision unit is added to the first record set.

7. The anti-collision operation planning method for fiber optic operation of a multi-object fiber optic spectroscopic telescope according to claim 5, characterized in that: In step (4.3), when repeating step (4.2), after each re-detection of the number of collided units contained in the collided unit set, the contents previously recorded in the second record set are deleted, and the new detection results are used to replace the previous detection results.

8. The collision-avoidance operation planning method for the operation of a multi-object fiber optic spectroscopic telescope according to claim 1, characterized in that: In step (5), the specific steps are as follows: (5.1) Rotate the unit to be processed 15° clockwise from its current position, and then redraw the complex graphic of the interference region in step (2) and perform overlap detection of the interference region in step (3); (5.2) If the result of the interference region overlap detection is that the interference region of the processed unit does not overlap with the interference region of other fiber optic positioning units, then the position of the processed unit after rotating 15° clockwise is used to replace the original target celestial body position of the processed unit, thus completing the collision avoidance of the processed unit. (5.3) If the result of the interference region overlap detection is that the interference region of the processed unit overlaps with the interference region of other fiber optic positioning units and the rotation angle is less than 360°, then repeat step (5.1); if the rotation angle is more than 360°, then the initial rotation angle is offset by 5° from the angle of the 15° clockwise rotation in step (5.1), and then repeat step (5.1) until the interference region of the processed unit does not overlap with the interference region of other fiber optic positioning units, and the position of the processed unit after rotation is used to replace the original celestial target position of the processed unit, and finally the collision avoidance of the processed unit is completed.

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