Large-tolerance deployable double-point special-shaped positioning and guiding mechanism and tolerance design method

Abstract

The present invention provides a large-tolerance deployable double-point special-shaped positioning and guiding mechanism and a tolerance design method. The mechanism comprises two sets of deployable positioning and guiding mechanisms with parallel and symmetric structures and similar structures, both of which are composed of an active end and a passive end. The passive end includes a base and a guiding column, and is fixed on the outer platform of the cabin. The active end includes a deployable mechanism, a compression and release mechanism, a connecting rod, a positioning and guiding hole, and a visualization window, and is connected to a space payload. The guiding column corresponds to the guiding hole and is divided into a small column section, a large column section, and a transition section. The positioning and guiding mechanism is divided into a fixed and a floating fit, and the corresponding positioning and guiding holes are circular and waist-shaped respectively. The present invention saves space, has a large deployment stroke, controllable speed, improves the bending and torsion resistance capabilities of the space payload, makes it have the characteristics of large stiffness, reliable connection, etc., and has a large tolerance adaptation ability during guiding, can better realize the positioning and guiding function, and provides technical support for installing a large space payload at a set position outside the spacecraft cabin.

Description

Technical Field

[0001] The present invention relates to the technical field of on-orbit maintenance and construction of space stations and space payloads, and particularly to a large-tolerance deployable double-point special-shaped positioning and guiding mechanism and a tolerance design method in space, which are applicable to the tasks of astronauts' spacewalks to complete the on-orbit assembly and construction of large space payloads and spacecrafts. Background Art

[0002] As a typical representative of extravehicular equipment, the performance indicators of space payloads have been increasing day by day, resulting in a significant increase in their structural volume. Traditional launch vehicles and common space deployment mechanisms are difficult to meet the requirements of the launch section size envelope of large-scale space payloads and the needs of on-orbit assembly and maintenance.

[0003] Currently, the research on on-orbit positioning and guiding technologies mostly focuses on small guiding interfaces and single-point guiding technologies. The guiding and docking of space payloads and spacecrafts are mostly achieved through the combination of robotic arms and mechanical components. The mechanism is relatively complex, and the single-point guiding connection method in large-scale guiding docking has poor bending moment bearing capacity and is difficult to meet the stiffness requirements. The relevant patents on space payload positioning and guiding mechanisms in China are as follows: Harbin Institute of Technology, a large-tolerance docking and capturing device for large space robotic arms and rendezvous and docking. The patent involved in this research is applicable to small-inertia and unpowered targets floating freely in space. It drives 3 fingers by a motor to adapt to the guiding tolerance, and is not suitable for large-scale extravehicular equipment and extravehicular activities applications; Harbin Institute of Technology, a rotary T-head type space docking lock and release mechanism. The patent involved in this research realizes repeated locking and releasing by driving the rotation of the T-head, and uses a single-point single-cone head-cone hole configuration to adapt to the guiding tolerance. It is difficult to bear the large bending moment and torque after locking large-scale payloads, and lacks corresponding ergonomic designs; Beijing Institute of Spacecraft System Engineering, a berthing device for docking a pallet with a space station. The patent involved in this research adopts a "short and thick" dumbbell-shaped layout to connect large payloads and the cabin body, and improves the bearing capacity of single-point connection through a compact structure, but it is difficult to meet the safety distance requirements such as thermal control implementation and electromagnetic compatibility between large-scale payloads and the cabin body. Summary of the Invention

[0004] The embodiments of the present invention provide a large-tolerance deployable double-point special-shaped positioning and guiding mechanism and a tolerance design method, which can not only improve the bending and torsion resistance of space payloads, making them have the characteristics of large stiffness and reliable connection, but also the mechanism saves space, has a large deployment stroke, controllable speed, weak impact, and has a large-tolerance adaptation ability, and can better realize the positioning and guiding function of large space payloads and spacecraft cabin platforms, thereby providing technical support for installing large space payloads at set positions outside the spacecraft cabin.

[0005] To achieve the above-mentioned inventive objectives, the technical solutions provided by the embodiments of the present invention are as follows:

[0006] A large-tolerance deployable double-point non-circular positioning and guiding mechanism, comprising two sets of deployable positioning and guiding mechanisms with similar constituent structures arranged in parallel and symmetrically. The positioning and guiding mechanism includes a passive end and an active end;

[0007] The passive end includes a passive-end base, one end of the passive-end base is connected with a passive-end guiding column, and the other end of the passive-end base is fixed on the outer platform of the spacecraft cabin;

[0008] The active end includes a deployable mechanism, one end of the deployable mechanism is connected with a connecting rod, a compression and release mechanism is installed on the connecting rod, and one end of the connecting rod is connected with a positioning and guiding hole. A visualization window is arranged on the side of the positioning and guiding hole. The deployable mechanism is fixedly connected with the space payload and can deploy the space payload by 180°;

[0009] The passive-end guiding column includes a fine-guiding large-column section, a tapered guiding transition section, and a coarse-guiding small-column section. The positioning and guiding hole includes a large-column section hole, a tapered guiding hole, and a small-column section hole;

[0010] The large-tolerance deployable double-point non-circular positioning and guiding mechanism adopts a double-point positioning and guiding configuration of one-point fixed and one-point floating. The cooperation between the active end and the passive end of one set of the positioning and guiding mechanism is a fixed mode, and both the large-column section hole and the small-column section hole of the positioning and guiding hole are circular holes; the cooperation between the active end and the passive end of the other set of the positioning and guiding mechanism is a floating mode, and both the large-column section hole and the small-column section hole of the positioning and guiding hole are waist-shaped holes and have a gap.

[0011] Exemplarily, the deployable mechanism includes a male hinge assembly and a female hinge assembly; the mounting flange at one end of the male hinge assembly is connected with the mounting surface of the space payload, and a rotating hole is arranged at the other end. A rotating shaft is arranged at one end of the female hinge assembly. The rotating hole and the rotating shaft are in clearance fit. The mounting flange at the other end of the female hinge assembly is connected with the mounting flange on the connecting rod.

[0012] Exemplarily, a coil spring is arranged on the rotating shaft of the female hinge assembly. The female hinge assembly can deploy the space payload by 180° through the coil spring; a locking rod is arranged on the female hinge assembly. The locking rod rotates around the fixed shaft of the female hinge assembly through the coil spring. After the space payload is deployed in place, the locking rod enters the limit groove of the male hinge assembly.

[0013] Exemplarily, during the deployment process of the space payload, a microswitch on the female hinge assembly emits a signal indicating that the deployment is in place.

[0014] Exemplarily, one end of the rotating shaft is connected to a coupling assembly, the coupling assembly is connected to a damper, and the damper is connected to the rotating shaft of the female hinge assembly through the coupling assembly.

[0015] Exemplarily, the connecting rod is a hollow cuboid structure with flange surfaces at both ends. One end is fixedly connected to the positioning and guiding hole, and the other end is fixedly connected to the flange surface of the female hinge assembly of the deployable mechanism; a through hole is provided in the central part of the connecting rod, and a pressing and releasing mechanism is installed at one end of the through hole, and the pressing and releasing mechanism is connected to the pressing and releasing interface of the space payload.

[0016] Exemplarily, the pressing and releasing mechanism adopts a low-impact unlocking and releasing device based on shape memory alloy or a low-impact unlocking and releasing device based on other principles.

[0017] Exemplarily, multiple numbers on the visualization window correspond to different positions at the top of the passive end guiding column. Sorted from the docking end face to the mounting flange face, the number "1" indicates the start of the guiding process, the initial positioning of the active end and the passive end is completed, and the small rough guiding column section of the passive end guiding column enters the positioning and guiding hole of the active end; the number "2" indicates that the guiding and docking process is in progress and the large fine guiding column section of the passive end guiding column enters the positioning and guiding hole of the active end; the number "3" indicates the end of the positioning and guiding process.

[0018] A tolerance design method for a large tolerance deployable double-point special-shaped positioning and guiding mechanism, the method is used to design the large tolerance deployable double-point special-shaped positioning and guiding mechanism, and the method includes the following contents:

[0019] The double-point special-shaped positioning and guiding mechanism is divided into a positioning and guiding mechanism A and a positioning and guiding mechanism B. The positioning and guiding mechanism in which the cooperation between the active end and the passive end is a fixed mode is the positioning and guiding mechanism A, and the positioning and guiding mechanism in which the cooperation between the active end and the passive end is a floating mode is the positioning and guiding mechanism B;

[0020] The clearance of the large column section hole at the active end of the positioning and guiding mechanism A is set as Δd1, and the clearance of the small column section hole is set as Δd1', and it satisfies Δd1' >> Δd1; the clearance of the positioning and guiding hole at the active end of the positioning and guiding mechanism B adapts to the change of the relative pose of the passive end base. Among them, the large column section hole at the active end of the positioning and guiding mechanism B has a straight line section and an arc section, and the unilateral clearance of the straight line section Δd2 = 2Δd1, and the unilateral clearance of the arc section Δd3 = 2.5Δd1'; the small column section hole at the active end of the positioning and guiding mechanism B also has a straight line section and an arc section, the unilateral clearance of the straight line section Δd4 = 2Δd1', and the unilateral clearance of the arc section Δd5 = 3Δd1'; among them, the multiple relationship is not limited to the above specific values and can be adjusted according to the envelope size and tolerance requirements.

[0021] Exemplarily, a docking coordinate system is defined. The midpoint of the connection line between the centers of the passive end guiding columns of the positioning and guiding mechanism A and the centers of the passive end guiding columns of the positioning and guiding mechanism B projected on the guiding surface is used as the origin. In the guiding surface, the direction from the center of the passive end guiding column of the positioning and guiding mechanism A to the center of the passive end guiding column of the positioning and guiding mechanism B is the Y direction, and the theoretical guiding direction from the passive end to the active end is the X direction. The Z direction is determined by the right-hand rule;

[0022] The projection of the center of the passive end guiding column of the positioning and guiding mechanism A on the guiding surface is denoted as O1, and the projection of the center of the passive end guiding column of the positioning and guiding mechanism B on the docking surface is denoted as O2. The distance between the center of the passive end guiding column of the positioning and guiding mechanism A and the center of the passive end guiding column of the positioning and guiding mechanism B is L;

[0023] According to the design of the unilateral clearance of the large column section hole at the active end of the positioning and guiding mechanism B, the tolerance along the Y direction ΔY = ±Δd3 = ±2.5Δd1'; let the deflection angle of the space payload outside the cabin be θ, and the tolerance along the Z direction ΔZ ≥ L × tanθ;

[0024] The space payload connected by the positioning and guiding mechanism A and the positioning and guiding mechanism B can rotate around the X axis in the YOZ plane, so that the passive end guiding column falls into the positioning and guiding hole at the active end. The center of the passive end guiding column of the positioning and guiding mechanism B moves from O2 to O2'. Therefore, the following should be satisfied simultaneously:

[0025] The rotational tolerance around the Y direction is mainly determined by the Z-direction clearance Δd2 between the fine guiding large column section of the passive end guiding column of the positioning and guiding mechanism B and the large column section hole at the active end. The length of the mating section is denoted as p, then ΔRY = ±arctan(p / Δd2);

[0026] The rotation tolerance around the Z direction is mainly determined by the Y-direction gap Δd5 between the coarse guide small column segment of the passive end guide column of the positioning guide mechanism B and the small column segment hole of the active end. The single-side gap is 3 times Δd1', where the combined length of the coarse guide small column segment and the fine guide large column segment of the passive end guide column is denoted as q, then ΔRZ = ±arctan(q / 3Δd1');

[0027] Among them, ΔRY is the rotation tolerance of the space payload at the passive end around the Y direction, and ΔRZ is the rotation tolerance of the space payload at the passive end around the Z direction.

[0028] Compared with the prior art, the above technical solution has at least the following beneficial effects:

[0029] The above scheme, large tolerance expandable double-point special-shaped positioning and guiding mechanism:

[0030] 1. Save space: The mechanism gathers the large space payload in the launch section and the transfer section through a compression release mechanism based on the low-impact unlocking and releasing principle of shape memory alloys, etc., withstands the overload of the launch end, reduces the transportation envelope requirements and can effectively reduce the impact load during unlocking. It can be reused many times and is particularly suitable for the on-orbit assembly and construction of large-scale space payloads.

[0031] 2. Large deployment stroke and controllable speed: After the mechanism is unlocked, the large equipment can be deployed 180° through the coil spring in the deployable mechanism. The deployment speed can be controlled by the damper. The entire deployment process has little impact on the payload outside the cabin. It has the characteristics of large deployment stroke, weak impact and controllable speed.

[0032] 3. Reliable connection: The mechanism improves the bending and torsion resistance of the space payload through the configuration of double-point guide connection, and has the characteristics of high rigidity and reliable connection.

[0033] The above scheme, the tolerance design method of the large-tolerance expandable two-point special-shaped positioning and guiding mechanism: has large tolerance adaptability: the mechanism improves the guidance tolerance in multiple degrees of freedom directions through the design of large-clearance waist-shaped holes, so that the large space payload has large tolerance adaptability during the active and passive end guidance docking process, and the tolerance capability can be quantified in design, which is suitable for the needs of large astronaut operation errors, two-person collaborative assembly and high-precision posture maintenance after docking of space payloads. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0035] Figure 1 Schematic diagram of the retracted state of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention during launch and transportation;

[0036] Figure 2 Schematic diagram of the deployed state of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention during operation;

[0037] Figure 3 Schematic diagram of the composition of the single - side passive end of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention;

[0038] Figure 4 is a schematic diagram of the composition of the single - side active end of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention. a) is the front view of the single - side active end, and b) is the top view of the single - side active end;

[0039] Figure 5 Schematic diagram of the composition of the deployable mechanism of the single - side active end of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention;

[0040] Figure 6 External view of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention after the single - side deployable positioning and guiding mechanism is guided and docked;

[0041] Figure 7 Schematic diagram of the tolerance gap design of the large column section of the deployable double - point special - shaped positioning and guiding mechanism in the tolerance design method of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention;

[0042] Figure 8 Schematic diagram of the tolerance gap design of the small column section of the deployable double - point special - shaped positioning and guiding mechanism in the tolerance design method of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention;

[0043] Figure 9 Schematic diagram of the combined length of the matching section length of the positioning and guiding mechanism B and the rough - guiding small column section and the fine - guiding large column section of the passive - end guiding column in the tolerance design method of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention;

[0044] Figure 10 Schematic diagram of the tolerance design of the position along the Z - direction of the deployable double - point special - shaped positioning and guiding mechanism in the tolerance design method of the large tolerance deployable double - point special - shaped positioning and guiding mechanism of the present invention.

[0045] The reference numerals are explained as follows:

[0046] 100, passive end; 101, passive end base; 102, passive end guide post; 103, large precision guide post section; 104, tapered guide transition section; 105, small rough guide post section; 200, active end; 210, deployable mechanism; 211, male hinge assembly; 212, female hinge assembly; 213, coupling assembly; 214, damper; 215, rotation hole; 216, rotating shaft; 217, coil spring; 218, microswitch; 219, locking rod; 220, pressing and releasing mechanism; 230, connecting rod; 240, positioning and guiding hole; 250, visualization window; 300, extravehicular platform of spacecraft; 400, space payload; a, before rotation; b, after rotation. Detailed implementation manners

[0047] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0048] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, the terms such as "a", "an" or "the" do not denote a quantity limitation, but mean that there is at least one. The terms such as "include" or "comprise" mean that the elements or items appearing before this word cover the elements or items listed after this word and their equivalents, without excluding other elements or items. The terms such as "connect" or "couple" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0049] It should be noted that the "upper", "lower", "left", "right", "front" and "back" used in the present invention are only used to represent relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0050] In view of the current research on on-orbit positioning and guiding technologies mainly focusing on small guiding interfaces and single-point guiding technologies, which have complex mechanisms, and the single-point guiding connection method in large-scale guiding docking has poor bending moment bearing capacity and difficulty in meeting stiffness requirements, etc., the present invention provides a large-tolerance deployable double-point special-shaped positioning and guiding mechanism and a tolerance design method that can improve the bending and torsion resistance of space payloads, making them characterized by large stiffness, reliable connection, etc., saving space, having a large deployment stroke, controllable speed, weak impact, and large tolerance adaptation ability, and being able to better realize the positioning and guiding function of large space payloads and spacecraft cabin platforms, thereby providing technical support for installing large space payloads at set positions outside the spacecraft cabin.

[0051] As Figures 1 to 6 shown, the embodiment of the present invention provides a large-tolerance deployable double-point special-shaped positioning and guiding mechanism, which includes two sets of deployable positioning and guiding mechanisms that are parallel, symmetric, and have similar constituent structures, respectively denoted as positioning and guiding mechanism A and positioning and guiding mechanism B, both of which include a passive end 100 and an active end 200.

[0052] The passive end 100 includes a passive end base 101. One end of the passive end base 101 is connected with a passive end guiding column 102, and the other end of the passive end base 101 is fixed at a set position on the outer platform 300 of the spacecraft cabin through bolts.

[0053] The active end 200 includes a deployable mechanism 210. One end of the deployable mechanism 210 is connected with a connecting rod 230. A pressing and releasing mechanism 220 is installed on the connecting rod 230, and one end of the connecting rod 230 is connected with a positioning and guiding hole 240. A visualization window 250 is provided on the side of the positioning and guiding hole 240. Except for the positioning and guiding hole 240, the remaining constituent structures of the active ends 200 of the positioning and guiding mechanism A and the positioning and guiding mechanism B are the same and are fixedly connected with the space payload 400 through the deployable mechanism 210.

[0054] The passive end guiding column 102 corresponds to the positioning guiding hole 240. The passive end guiding column 102 includes a fine guiding large column section 103, a tapered guiding transition section 104, and a coarse guiding small column section 105, which play a role in precise guiding and positioning. The positioning guiding hole 240 includes a large column section hole, a tapered guiding hole, and a small column section hole. The large tolerance expandable double-point special-shaped positioning guiding mechanism adopts a double-point positioning guiding configuration with one point fixed and one point floating. The cooperation between the main and passive ends 200 and 100 of the positioning guiding mechanism A is a fixed mode, and the cooperation between the main and passive ends 200 and 100 of the positioning guiding mechanism B is a floating mode. The large column section hole and the small column section hole of the positioning guiding hole 240 of the positioning guiding mechanism A are both circular holes, and the large column section hole and the small column section hole of the positioning guiding hole 240 of the positioning guiding mechanism B are both waist-shaped holes with a large gap left. The large-gap waist-shaped hole improves the guiding tolerance in multiple degrees of freedom directions. During the positioning and guiding process of the main and passive ends 200 and 100, it has a large tolerance adaptation ability, and the tolerance ability can be quantitatively designed, which is applicable to the high-precision pose maintenance requirements after the large visual operation error of astronauts during extravehicular activities, double-person collaborative assembly, and the guiding and docking of space payloads.

[0055] A visualization window 250 is provided on the side of the positioning guiding hole 240 for observing the current guiding depth. Multiple numbers on the visualization window 250 correspond to different positions at the top of the passive end guiding column 102. Sorted from the docking end face to the installation flange face, the number "1" indicates the start of the guiding process, the initial positioning of the main and passive ends 200 and 100 is completed, and the coarse guiding small column section 105 of the passive end guiding column 102 enters the positioning guiding hole 240 of the active end 200. The number "2" indicates that the guiding docking process is in progress and the fine guiding large column section 103 of the passive end guiding column 102 enters the positioning guiding hole 240 of the active end 200. The number "3" indicates the end of the positioning guiding process.

[0056] The deployable mechanism 210 includes a male hinge assembly 211 and a female hinge assembly 212; a mounting flange on one end of the male hinge assembly 211 is connected to the mounting surface of the space payload 400, and a rotation hole 215 is provided at the other end; a rotation shaft 216 is provided at one end of the female hinge assembly 212, and the rotation hole 215 and the rotation shaft 216 are clearance-matched, and a mounting flange on the other end of the female hinge assembly 212 is connected to a mounting flange on the connecting rod 230; a coil spring 217 is provided on the rotation shaft 216, and the female hinge assembly 2 12 The space payload 400 can be unfolded 180° through the coil spring 217, and a signal of full unfolding is sent through the micro switch 218 on the mother hinge assembly 212, which is used for monitoring the state of the mechanism; the mother hinge assembly 212 is provided with a locking rod 219, and the locking rod 219 rotates around the fixed axis of the mother hinge assembly 212 through the coil spring 217. After the space payload 400 is fully unfolded, the locking rod 219 enters the limit groove of the male hinge assembly 211 and plays a locking role after the full unfolding. One end of the rotating shaft 216 is connected to a coupling assembly 213, and the coupling assembly 213 is connected to a damper 214. The damper 214 is connected to the rotating shaft 216 on the mother hinge assembly 212 through the coupling assembly 213; the damper 214 provides rotation damping for the unfoldable mechanism 210, reduces its rotation speed, and reduces the impact of the device during the 180° rotation and unfolding process.

[0057] The connecting rod 230 is a hollow rectangular structure with flange surfaces at both ends. One end is connected to the positioning guide hole 240, and the other end is connected to the flange surface on the mother hinge assembly 212 of the deployable mechanism 210. The connecting rod 230 provides support and transmits torque. A through hole is provided at the center of the connecting rod 230, and the clamping and releasing mechanism 220 is installed at one end of the through hole. The clamping and releasing mechanism 220 is connected to the clamping and releasing interface of the space payload 400.

[0058] The clamping release mechanism 220 adopts a low-impact unlocking and releasing device based on shape memory alloy or a low-impact unlocking and releasing device based on other principles, which can effectively reduce the impact load during unlocking and can be reused many times; during the launch and transportation process of the guide mechanism, the clamping release mechanism 220 can be used to gather the large space payload 400, withstand the overload of the launch end, and reduce the transportation envelope requirements, which is particularly suitable for the on-orbit assembly of the large space payload 400.

[0059] Compared with the traditional single-point positioning and guiding mechanism, the large-tolerance deployable double-point special-shaped positioning and guiding mechanism provided by the embodiment of the present invention adopts a parallel symmetric double-point positioning and guiding mechanism configuration, which improves the bending and torsion resistance of the space payload 400, making it have the characteristics of high stiffness and reliable connection, and is more suitable for the assembly and construction of large space payloads 400.

[0060] As Figures 7 to 10 shown, the embodiment of the present invention provides a tolerance design method for a large-tolerance deployable double-point special-shaped positioning and guiding mechanism, including the following: In the taper hole fit of the main and passive ends 200 and 100 of the embodiment of the present invention, the thick guiding small column section 105 is a rough fit, mainly for positioning and guiding, and the fine guiding large column section 103 is a fine fit to ensure guiding accuracy; the active end 200 of the positioning and guiding mechanism A is a fixed end, where the clearance of the large column section hole is set as Δd1, the clearance of the small column section hole is larger, set as Δd1', and Δd1' >> Δd1 is satisfied.

[0061] The active end 200 of the positioning and guiding mechanism B is a floating end, and the clearance of the floating end adapts to the relative pose change of the passive end base 101. Among them, the large column section hole of the positioning and guiding mechanism B is set as an oval hole, and there is a clearance on the straight section of the oval hole, with a unilateral clearance Δd2 = 2Δd1; there is a larger clearance on the arc section, with a unilateral clearance Δd3 = 2.5Δd1'; the small column section hole of the positioning and guiding mechanism B is also an oval hole, and there is a clearance on the straight section of the oval hole, with a unilateral clearance Δd4 = 2Δd1', and there is a clearance on the arc section, with a unilateral clearance Δd5 = 3Δd1'; among them, the multiple relationship is not limited to the above specific values and can be adjusted according to the envelope size and tolerance requirements.

[0062] During the tolerance analysis process, according to the relative motion theory, the active ends 200 of the positioning and guiding mechanism A and the positioning and guiding mechanism B are fixed to the theoretical pose, the pose of the passive end 100 of the positioning and guiding mechanism A is fixed, and a single variable in the six-degree-of-freedom pose of the passive end 100 of the positioning and guiding mechanism B relative to the passive end 100 of the positioning and guiding mechanism A is adjusted respectively, and the relative pose change amounts of the other five degrees of freedom are theoretical values of 0 for the tolerance analysis of a single variable.

[0063] Define the docking coordinate system. Take the projection of the midpoint of the line connecting the centers of the passive end guide columns 102 of the positioning and guiding mechanism A and the centers of the passive end guide columns 102 of the positioning and guiding mechanism B on the guiding surface as the origin. In the guiding surface, the direction from the center of the passive end guide column 102 of the positioning and guiding mechanism A to the center of the passive end guide column 102 of the positioning and guiding mechanism B is the Y direction, and the theoretical guiding direction from the passive end 100 to the active end 200 is the X direction. The Z direction is determined by the right-hand rule. The projection of the center of the passive end guide column 102 of the positioning and guiding mechanism A on the guiding surface is denoted as O1, and the projection of the center of the passive end guide column 102 of the positioning and guiding mechanism B on the docking surface is denoted as O2. Let the distance between the centers of the passive end guide columns 102 of the positioning and guiding mechanism A and the centers of the passive end guide columns 102 of the positioning and guiding mechanism B be L.

[0064] According to the design of the unilateral clearance of the large column section hole of the positioning and guiding mechanism B, the tolerance in the Y direction is ΔY = ±Δd3 = ±2.5Δd1'.

[0065] The tolerance in the Z direction should meet the accuracy requirements of the space payload 400. Let the deflection angle of the extravehicular payload be θ, then the tolerance in the Z direction should meet ΔZ ≥ L × tanθ. At the same time, making full use of the shape characteristics of the cylindrical passive end guide column 102 and the accessibility of large-scale dual-operator cooperation, the combination of the space payload 400 connected to the active end 200 of the positioning and guiding mechanism A and the positioning and guiding mechanism B can rotate around the X axis in the YOZ plane, so that the passive end guide column 102 falls into the positioning guide hole 240, and the center of the passive end guide column 102 of the positioning and guiding mechanism B moves from O2 to O2'. Therefore, the following should be met simultaneously.

[0066] The rotational tolerance around the Y direction is mainly determined by the Z-direction clearance Δd2 between the precise guiding large column section 103 of the positioning and guiding mechanism B and the large column section hole of the positioning and guiding mechanism B. The length of the mating section is denoted as p, then ΔRY = ±arctan(p / Δd2).

[0067] Before the rotation of the positioning and guiding mechanism B is a, and after the rotation is b. The rotational tolerance around the Z direction is mainly determined by the Y-direction clearance Δd5 between the rough guiding small column section 105 of the positioning and guiding mechanism B and the small column section hole of the positioning and guiding mechanism B. The unilateral clearance is 3 times Δd1'. The combined length of the rough and precise mating sections of the passive end guide column 102 is denoted as q, then ΔRZ = ±arctan(q / 3Δd1').

[0068] The tolerance design method of the large-tolerance deployable double-point special-shaped positioning and guiding mechanism provided by the embodiments of the present invention has the ability to adapt to large tolerances. The mechanism improves the guiding tolerance in multiple degrees of freedom directions through the design of large-gap waist-shaped holes, enabling the large space payload 400 to have the ability to adapt to large tolerances during the guiding docking process between the main and passive ends 200 and 100. Moreover, the tolerance ability can be quantitatively designed, which is applicable to the requirements of large operation errors of astronauts, double-person collaborative assembly, and high-precision pose maintenance after the docking of space payloads.

[0069] The working process of the large-tolerance deployable double-point special-shaped positioning and guiding mechanism and its tolerance design method of the present invention is as follows:

[0070] The active end of the deployable positioning and guiding mechanism is fixedly connected to the space payload. With the assistance of an external space manipulator or the support of an astronaut's extravehicular activity, it is transported near the active end of the deployable positioning and guiding mechanism. After low-impact unlocking using a coil spring through the compression and release mechanism on the active end, it is unfolded by 180° by the deployable mechanism on the active end, and the deployable double-point special-shaped positioning and guiding mechanism changes from the retracted state to the deployed state.

[0071] Subsequently, the astronaut conducts an extravehicular activity in space, approaches the passive end of the large-tolerance positioning and guiding mechanism, holds the positioning and guiding hole of the active end with one or both hands, observes and roughly adjusts the pose of the active end to be initially aligned with the passive end and enter the positioning and guiding domain. The astronaut applies an operating force to push the combination of the active end and the space payload towards the passive end. According to the visual window on the active end, the insertion depth of the guiding column at the passive end can be observed, and the current guiding docking state can be visually judged to achieve the positioning and guiding docking of the main and passive ends.

[0072] The following points need to be explained:

[0073] (1) The attached drawings of the embodiments of the present invention only relate to the structures involved in the embodiments of the present invention, and other structures can refer to the usual designs.

[0074] (2) For clarity, in the attached drawings used to describe the embodiments of the present invention, the thickness of layers or regions is enlarged or reduced, that is, these drawings are not drawn according to the actual scale. It can be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, the element can be "directly" on or under the other element or there can be intermediate elements.

[0075] (3) Without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0076] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The large-tolerance deployable double-point special-shaped positioning and guiding mechanism is characterized in that It includes two sets of expandable positioning and guiding mechanisms with similar composition structures arranged in parallel and symmetrically. The positioning and guiding mechanism includes a passive end and an active end; The passive end includes a passive end base. One end of the passive end base is connected with a passive end guiding column, and the other end of the passive end base is fixed on the outer platform of the spacecraft cabin; The active end includes an expandable mechanism. One end of the expandable mechanism is connected with a connecting rod. A compression and release mechanism is installed on the connecting rod, and one end of the connecting rod is connected with a positioning and guiding hole. A visualization window is arranged on the side of the positioning and guiding hole. The expandable mechanism is fixedly connected with the space payload and can expand the space payload by 180°; The passive end guiding column includes a fine guiding large column section, a conical guiding transition section and a coarse guiding small column section. The positioning and guiding hole includes a large column section hole, a conical guiding hole and a small column section hole; The large tolerance expandable double-point special-shaped positioning and guiding mechanism adopts a double-point positioning and guiding configuration of one point fixed and one point floating. The cooperation between the active end and the passive end of one set of the positioning and guiding mechanism is in a fixed manner, and both the large column section hole and the small column section hole of the positioning and guiding hole are circular holes; the cooperation between the active end and the passive end of the other set of the positioning and guiding mechanism is in a floating manner, and both the large column section hole and the small column section hole of the positioning and guiding hole are waist-shaped holes and there is a gap left.

2. The large tolerance deployable double-point special-shaped positioning and guiding mechanism according to claim 1, characterized in that, The expandable mechanism includes a male hinge assembly and a female hinge assembly; the mounting flange at one end of the male hinge assembly is connected with the mounting surface of the space payload, and a rotating hole is arranged at the other end. A rotating shaft is arranged at one end of the female hinge assembly. The rotating hole and the rotating shaft are in clearance fit. The mounting flange at the other end of the female hinge assembly is connected with the mounting flange on the connecting rod.

3. The large-tolerance deployable double-point special-shaped positioning and guiding mechanism according to claim 2, characterized in that, A coil spring is arranged on the rotating shaft of the female hinge assembly. The female hinge assembly can expand the space payload by 180° through the coil spring; a locking rod is arranged on the female hinge assembly. The locking rod rotates around the fixed shaft of the female hinge assembly through the coil spring. After the space payload is expanded in place, the locking rod enters the limit groove of the male hinge assembly.

4. The large-tolerance deployable double-point non-uniform positioning and guiding mechanism according to claim 3, characterized in that, During the expansion process of the space payload, a microswitch on the female hinge assembly sends a signal indicating that the expansion is in place.

5. The large tolerance deployable double-point non-uniform positioning and guiding mechanism according to claim 2, characterized in that, One end of the rotating shaft is connected with a coupling assembly, and the coupling assembly is connected with a damper. The damper is connected with the rotating shaft of the female hinge assembly through the coupling assembly.

6. The large tolerance deployable double-point special-shaped positioning and guiding mechanism according to claim 1, characterized in that The connecting rod is of a hollow cuboid structure, and both ends are flange surfaces. One end is fixedly connected with the positioning and guiding hole, and the other end is fixedly connected with the flange surface of the female hinge assembly of the expandable mechanism; a through hole is arranged at the central part of the connecting rod. A compression and release mechanism is installed at one end of the through hole, and the compression and release mechanism is connected with the compression and release interface of the space payload.

7. The large-tolerance deployable double-point special-shaped positioning and guiding mechanism according to claim 5, characterized in that, The compression and release mechanism adopts a low-impact unlocking and releasing device based on a shape memory alloy or a low-impact unlocking and releasing device based on other principles.

8. The expandable double-point non-uniform positioning and guiding mechanism with large tolerance according to claim 1, characterized in that, Multiple numbers on the visualization window correspond to different positions at the top of the passive-end guiding column. Sorted from the docking end face to the mounting flange face, the number "1" indicates the start of the guiding process, when the initial positioning of the active end and the passive end is completed and the small rough-guiding column section of the passive-end guiding column enters the positioning guiding hole of the active end; the number "2" indicates that the guiding docking process is in progress and the large fine-guiding column section of the passive-end guiding column enters the positioning guiding hole of the active end; the number "3" indicates the end of the positioning guiding process.

9. Tolerance design method for a large-tolerance deployable double-point special-shaped positioning and guiding mechanism, characterized in that, The method is used to design the large-tolerance deployable double-point special-shaped positioning guiding mechanism according to any one of claims 1 to 8, and the method includes the following contents: The double-point special-shaped positioning guiding mechanism is divided into a positioning guiding mechanism A and a positioning guiding mechanism B. The positioning guiding mechanism in which the cooperation between the active end and the passive end is a fixed mode is the positioning guiding mechanism A, and the positioning guiding mechanism in which the cooperation between the active end and the passive end is a floating mode is the positioning guiding mechanism B; The clearance of the large column section hole of the active end of the positioning guiding mechanism A is set as Δd1, and the clearance of the small column section hole is set as Δd1', and Δd1' >> Δd1 is satisfied; the clearance of the positioning guiding hole of the active end of the positioning guiding mechanism B adapts to the change of the relative pose of the passive end base. Among them, the large column section hole of the active end of the positioning guiding mechanism B has a straight line section and an arc section, and the unilateral clearance of the straight line section Δd2 = 2Δd1, and the unilateral clearance of the arc section Δd3 = 2.5Δd1'; the small column section hole of the active end of the positioning guiding mechanism B also has a straight line section and an arc section, and the unilateral clearance of the straight line section Δd4 = 2Δd1', and the unilateral clearance of the arc section Δd5 = 3Δd1'.

10. The tolerance design method of the large tolerance deployable double-point special-shaped positioning and guiding mechanism according to claim 9, characterized in that Define the docking coordinate system. The projection of the midpoint of the line connecting the centers of the passive-end guiding columns of the positioning guiding mechanism A and the centers of the passive-end guiding columns of the positioning guiding mechanism B on the guiding surface is used as the origin. In the guiding surface, the direction from the center of the passive-end guiding column of the positioning guiding mechanism A to the center of the passive-end guiding column of the positioning guiding mechanism B is the Y direction, and the theoretical guiding direction from the passive end to the active end is the X direction. The Z direction is determined by the right-hand rule; The projection of the center of the passive-end guiding column of the positioning guiding mechanism A on the guiding surface is denoted as O1, the projection of the center of the passive-end guiding column of the positioning guiding mechanism B on the docking surface is denoted as O2, and the distance between the center of the passive-end guiding column of the positioning guiding mechanism A and the center of the passive-end guiding column of the positioning guiding mechanism B is L; According to the design of the unilateral clearance of the large column section hole of the active end of the positioning guiding mechanism B, the tolerance along the Y direction ΔY = ±Δd3 = ±2.5Δd1'; let the deflection angle of the space payload outside the cabin be θ, and the tolerance along the Z direction ΔZ ≥ L × tanθ; The space payload connected to the positioning and guiding mechanism A and the positioning and guiding mechanism B can rotate around the X-axis in the YOZ plane, so that the passive end guiding column falls into the positioning and guiding hole of the active end. The center of the passive end guiding column of the positioning and guiding mechanism B moves from O2 to O2'. Therefore, the following conditions should be met simultaneously: The rotational tolerance around the Y direction is mainly determined by the Z-direction clearance Δd2 between the fine guiding large column section of the passive end guiding column of the positioning and guiding mechanism B and the large column section hole of the active end. If the length of the mating section is denoted as p, then ΔRY = ±arctan(p / Δd2); The rotational tolerance around the Z direction is mainly determined by the Y-direction clearance Δd5 between the rough guiding small column section of the passive end guiding column of the positioning and guiding mechanism B and the small column section hole of the active end. The unilateral clearance is 3 times Δd1'. If the combined length of the rough guiding small column section and the fine guiding large column section of the passive end guiding column is denoted as q, then ΔRZ = ±arctan(q / 3Δd1'); Among them, ΔRY is the rotational tolerance of the space payload at the passive end around the Y direction, and ΔRZ is the rotational tolerance of the space payload at the passive end around the Z direction.

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