A passive-active integrated magnetic suspension five-overload platform based on parallel mechanism

Abstract

The application relates to the field of aerospace technology, in particular to a passive and active integrated magnetic suspension five-super-load platform based on a parallel mechanism. The passive and active integrated magnetic suspension five-super-load platform comprises a parallel mechanism frame and a magnetic suspension super platform which are connected with each other, the parallel mechanism frame is further connected with a satellite body, and the magnetic suspension super platform is further connected with a load; the parallel mechanism frame comprises a plurality of branch chains and is used for providing attitude maneuvering capability for the magnetic suspension super platform; the magnetic suspension super platform comprises a magnetic suspension vibration isolator, a voice coil motor, a magnetic suspension moving platform and magnetic damping; the magnetic suspension moving platform is used for mounting the load; the voice coil motor is connected with the magnetic suspension moving platform and the parallel mechanism frame respectively, and is used for providing active adjustment of the magnetic suspension moving platform; and the magnetic suspension vibration isolator is used for reducing vibration in the moving process. When the attitude is not actively adjusted and the vibration is not actively inhibited, the magnetic suspension of the load and the platform can be maintained by less control, the transmission of the vibration can be physically blocked, and therefore energy consumption is saved.

Description

TECHNICAL FIELD

[0001] The application relates to the field of aerospace technology, in particular to a passive-active integrated magnetic suspension five-overload platform based on a parallel mechanism. BACKGROUND

[0002] With the rapid development of aerospace technology, high-precision spacecraft such as high-resolution remote sensing satellites, laser communication satellites and space telescopes have higher and higher requirements for the attitude precision, stability, quietness and agility of the load. The traditional three-axis stabilized satellite mainly uses a flywheel or a control moment gyroscope (CMG) to realize the attitude maneuvering and stabilization of the platform, and then drives the camera and other loads to realize the attitude maneuvering and stabilization, so as to realize the pointing requirement of the load.

[0003] In view of the requirements of super-precision, super-stability, super-quietness, super-agility and super-wide pointing of the load attitude, passive vibration isolation, passive-active vibration isolation (such as 'three super': super-precision, super-stability and super-agility) and active vibration control (such as 'double super': super-precision and super-stability) under the driving of a control moment gyroscope are developed. The passive vibration isolation is mainly good for high-frequency vibration isolation, but it is powerless for low-frequency micro-vibration and amplifies the micro-vibration in the medium frequency band to a certain extent. The 'three super' platform is a passive-active integrated vibration isolation platform for attitude control through a CMG. The CMG is used to realize the attitude agility and super-wide attitude maneuvering of the satellite platform. Obviously, the control ability of the micro-vibration is further improved compared with the passive vibration isolation. The passive-active integrated vibration isolator is composed of a voice coil motor and a diaphragm spring, which can actively control the medium and low frequency vibration. Due to the existence of a certain support stiffness, the micro-vibration of the platform is still partially transmitted to the load. The super-agility performance is realized by driving the platform to rapidly maneuver through the CMG, and then driving the load to realize the so-called agile attitude maneuvering through the transmission of the 'three super' platform. The 'double super' uses active magnetic suspension to more thoroughly isolate the micro-vibration. When the attitude needs to be controlled, the magnetic suspension mechanism generates control force and torque. When the attitude is stabilized within a certain range, the magnetic suspension mechanism is powered off, and the load is in a floating state, so it is basically not affected by the micro-vibration of the platform. Obviously, the micro-vibration control is more thorough, but the load disturbance is not considered. Moreover, the attitude maneuvering is still indirectly realized by driving the platform to maneuver through the attitude control system of the platform. It can be seen that the passive vibration isolation, the 'three super' platform and the 'double super' platform all indirectly drive the load to realize the attitude control through the attitude maneuvering and stabilization of the satellite platform. The contradiction between the large inertia of the whole satellite and the limited control torque makes it difficult to realize higher agility and other super performances. SUMMARY

[0004] The embodiment of the present application provides a parallel mechanism-based active and passive integrated magnetic suspension five-super-load platform, which can maintain the magnetic suspension of the load and the platform by less control without active adjustment of the attitude and active inhibition of the vibration, can physically block the transmission of the vibration, and is more energy-saving.

[0005] The embodiment of the present application provides a parallel mechanism-based active and passive integrated magnetic suspension five-super-load platform, which can maintain the magnetic suspension of the load and the platform by less control without active adjustment of the attitude and active inhibition of the vibration, can physically block the transmission of the vibration, and is more energy-saving.

[0006] The parallel mechanism frame comprises a plurality of branch chains, and is used for providing attitude maneuvering capability for the magnetic suspension super platform, the magnetic suspension super platform comprises a magnetic suspension vibration isolator, a voice coil motor, a magnetic suspension moving platform and a magnetic damper, the magnetic suspension moving platform is used for mounting the load, the voice coil motor is connected with the magnetic suspension moving platform and the parallel mechanism frame respectively, and is used for providing active adjustment of the magnetic suspension moving platform capability, and the magnetic suspension vibration isolator is used for reducing vibration in the moving process.

[0007] In a possible design, the parallel mechanism frame comprises a parallel mechanism base, a grating code disc, a rotary motor, a lead screw, a nut, a damping rod, a hinge, a parallel mechanism moving platform and an electric cylinder.

[0008] The parallel mechanism frame adopts a 3-PURU / 1-PRU or 3-PURU / 1-RU multi-branch chain parallel configuration, so that the parallel mechanism frame realizes three-axis rotation freedom and large-angle rotation, the parallel mechanism base is triangular, two groups of rotary motors and the grating code disc are arranged at three vertices of the parallel mechanism base, the lead screw is arranged on each side of the parallel mechanism base, one end of each group of the rotary motor and the grating code disc is connected with one end of the lead screw to control the rotation of the lead screw according to a preset number of turns, one end of the damping rod is threadedly connected to the lead screw through the nut, and the other end of the damping rod is connected to the parallel mechanism moving platform through the hinge, the parallel mechanism moving platform is connected with the magnetic suspension moving platform through the voice coil motor and the magnetic suspension vibration isolator, and the electric cylinder is arranged in the middle of the parallel mechanism base.

[0009] The rotary motor drives the rotation of the lead screw, pushes the nut to translate, and then drives the rotation of the dynamic parallel mechanism moving platform through the hinge, so that the direction of the magnetic suspension super platform can be pointed to any continuous angle in a local area, and three-axis large-range attitude maneuvering of the load is realized.

[0010] In a possible design, the damping rod is composed of a spring damper, and is used for passively isolating medium and high frequency vibrations on the satellite.

[0011] In a possible design, the parallel mechanism frame comprises structural damping for dissipating the energy of local resonance and improving the super-stable and super-static performance of the load.

[0012] In a possible design, the magnetic suspension vibration isolator supports the magnetic suspension moving platform and the parallel mechanism moving platform in a non-contact manner through repulsion of permanent magnets to limit the relative position of the two within a certain range, forming a passive vibration isolation system.

[0013] In a possible design, the magnetic suspension vibration isolator comprises a mounting rod, a mounting sleeve, a first axial permanent magnet, a second axial permanent magnet, a magnetic shield ring, an inner radial permanent magnet, an outer radial permanent magnet, a sleeve, and a locking ring, the mounting sleeve is internally provided with the sleeve, the first axial permanent magnet is arranged in the middle of the sleeve, two second axial permanent magnets, two magnetic shield rings, two inner radial permanent magnets, two outer radial permanent magnets, and two locking rings are sequentially arranged on both sides of the first axial permanent magnet, respectively, the mounting rod is connected with the magnetic suspension moving platform, and the mounting sleeve is connected with the parallel mechanism moving platform.

[0014] In a possible design, the voice coil motor is used to provide 6 degrees of freedom of force and torque.

[0015] In a possible design, an axial direction of each voice coil motor is connected in parallel with a displacement sensor for detecting the axial relative position change of the voice coil motor.

[0016] In a possible design, the stator part of the voice coil motor is fixed to the parallel mechanism moving platform, and the rotor part of the voice coil motor is fixed to the magnetic suspension moving platform.

[0017] In a possible design, the voice coil motor comprises a first voice coil motor and a second voice coil motor, the axes of the first voice coil motor and the second voice coil motor are perpendicular, four first voice coil motors are used to control the axial yaw and axial movement of the magnetic suspension moving platform, and four second voice coil motors are used to control the translation in two horizontal directions and the rotation around the axial direction.

[0018] Compared with the prior art, the present application has at least the following beneficial effects:

[0019] The patent is directed to the existing attitude control system which drives the attitude maneuvering and stabilizing of the satellite whole star with large mass and large inertia, drives the attitude maneuvering and stabilizing of the load with small mass and small inertia, causes great waste of the weight, power consumption and other valuable resources on the star, and also makes the equipment on the star which does not need to maneuver to maneuver, and further forces these equipment to be cooperatively controlled, and also increases the control complexity. It can be seen that this traditional attitude control mode not only causes a large amount of waste, but also limits the attitude maneuvering acceleration and speed of the load; and the load and platform fixed connection mode makes the disturbance on the platform directly transmitted to the load, and affects the super-stable and super-static of the load attitude, and therefore the load direct attitude control mode with the load as the guide and the master-slave integrated magnetic suspension "super" platform based on the parallel mechanism for realizing the load direct attitude control mode are proposed. That is, the spatial parallel mechanism is adopted to realize the rapid yaw of the moving platform in the local spherical area at any continuous angle, so as to drive the load on the moving platform to have any pointing and rapid attitude maneuvering in the local spherical area, and realize the super-agile of the load; the master-slave integrated magnetic suspension super platform inside the moving platform can realize the real non-contact support, and also can realize the active vibration control, reduce the vibration transmission, and realize the super-stable and super-static of the load; the two-stage attitude control mode of the large-range attitude maneuvering of the parallel mechanism and the small-range attitude adjustment of the master-slave integrated magnetic suspension super platform inside the moving platform takes into account the agility and accuracy of the attitude control; and the platform can reduce the configuration requirements of the attitude control system on the spacecraft, and can reduce the weight and power consumption and other resources of the attitude control system. It can be seen that the present application better takes into account the attitude control requirements such as super-precision, super-stable, super-static and super-agile of the load and the cost such as weight and power consumption of the system. The present application can be adapted to the application requirements such as the high-resolution agile satellite and the precise strike weapon platform. It can be seen that the patent has obvious advantages in the method of directly driving the load for the load attitude control by taking the target as the guide and adopting the parallel mechanism and the master-slave integrated magnetic suspension. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0021] Figure 1 It is a layout schematic diagram of the super-platform robot satellite of the present application;

[0022] Figure 2 It is a three-chain parallel mechanism super-platform schematic diagram of the present application;

[0023] Figure 3 It is a three-chain parallel mechanism frame schematic diagram of the present application;

[0024] Figure 4 The internal structure diagram of the magnetic suspension super platform of the present application is shown in the figure.

[0025] Figure 5 The internal structure diagram of the passive magnetic suspension unit of the present application is shown in the figure.

[0026] Figure 6 The super platform robot satellite control system block diagram of the present application is shown in the figure.

[0027] In the figure:

[0028] 1-magnetic suspension five overload platform; 2-load; 3-satellite body; 4-parallel mechanism frame; 5-magnetic suspension super platform; 6-parallel mechanism base; 7-grating code disc; 8-rotary motor; 9-screw; 10-nut; 11-damping rod; 12-hinge; 13-parallel mechanism moving platform; 14-electric cylinder; 15-magnetic suspension vibration isolator; 16-first voice coil motor; 17-second voice coil motor; 18-magnetic suspension moving platform; 19-mounting rod; 20-mounting sleeve; 21-first axial permanent magnet; 22-second axial permanent magnet; 23-magnetic isolation ring; 24-inner radial permanent magnet; 25-outer radial permanent magnet; 26-sleeve; 27-locking ring. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the terms "first", "second" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" means two or more; the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "connection" can be fixed connection, or detachable connection, or integrally connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] In the description of the specification, it needs to be understood that the "upper", "lower" and other orientation words described in the embodiments of the application are described in the angle shown in the drawings, and should not be understood as a limitation on the embodiments of the application. In addition, in the context, it also needs to be understood that when referring to one element connected to another element "on" or "under", it can be directly connected to another element "on" or "under" through an intermediate element.

[0032] As described above, the traditional mode still has the following problems:

[0033] 1) The mass and moment of inertia and other parameters of the whole satellite are much larger than the mass characteristic parameters of the load. The limited angular momentum and control torque of the inertial actuator such as the control moment gyro on the satellite limit the attitude maneuvering acceleration and speed of the whole satellite. The average attitude maneuvering speed of the whole satellite is basically not more than 5° / s. It can be seen that the agility of the load also depends on the agility of the satellite platform, and the agility is still insufficient. It can be seen that the attitude control mode of driving the small load by the large platform causes the waste of angular momentum capacity and torque of attitude control, and also causes the waste of resources such as weight and power consumption of the attitude control system.

[0034] Table 1 Typical satellite platform super-agile maneuver performance index

[0035]

[0036] 2) The flexibility and small damping of the solar sail and other structures on the satellite often require several seconds for the satellite attitude stabilization, which to some extent weakens the attitude maneuvering agility and rapid stabilization of the whole satellite. It can be seen that the attitude maneuvering mode of driving the small load by the large platform causes the unnecessary large range of coordinated motion of the on-board components, especially the flexible components, which causes the increase of the stabilization time of the whole satellite. Similarly, it limits the agility and rapid stabilization of the satellite and the bandwidth of the control system on the satellite.

[0037] 3) The wideband micro-vibration generated by the high-speed rotating mechanism such as the flywheel and the CMG in the working process will affect the attitude of the platform, the pointing performance index of the load, and the imaging quality index of the camera. The traditional method for suppressing the vibration on the satellite mainly uses a dedicated vibration isolation device to isolate the micro-vibration in the vibration transmission path. However, the efficiency of the widely used contact type vibration isolation still needs to be improved.

[0038] 4) In the simplified configuration of the control moment gyro (CMG), the internal singularity problem limits the rapid maneuvering and other applications of the satellite to some extent; and the redundant configuration of the CMG increases the weight and power consumption of the satellite, so there is a difficult to reconcile contradiction between the resource consumption cost and the simplicity of application of the attitude control system based on the CMG, which is not conducive to wide promotion.

[0039] In summary, the traditional satellite platform attitude control indirectly to achieve the load attitude control mode of time-consuming, labor-intensive, uneconomical, not cost-effective, therefore need to be for the application requirements of the load, research load attitude control of new mechanism, to achieve the goal of rapid maneuvering and rapid stabilization of the load attitude.

[0040] Compared with the prior art, the patent has the following advantages:

[0041] (1) The traditional satellite attitude control strategy is mainly based on the satellite platform, that is, the whole drives the local attitude control, that is, it mainly relies on the flywheel or control moment gyro (CMG) and other actuators to drive the spacecraft to maneuver, and then drive the load with mass and moment of inertia much smaller than the mass and moment of inertia of the whole satellite and the whole device to maneuver and stabilize the attitude, which causes waste of attitude control system resources. The attitude control strategy of the patent is directly oriented to the load attitude, that is, it uses parallel mechanisms to drive the load to maneuver and stabilize the attitude quickly by borrowing force and torque from the satellite platform. That is, the spatial parallel mechanism is used to realize the continuous angular maneuvering and any pointing in the local larger spherical region of the load, and then the moving platform drives the magnetic suspension super platform to directly realize the super agile maneuvering of the load. Since the mass and moment of inertia of the load are much smaller than those of the whole satellite and the whole device, the control torque required for the direct attitude control of the load in the patent is much smaller, which can significantly reduce the configuration requirements of the CMG and other attitude actuator systems.

[0042] (2) The traditional attitude control mode of pulling one hair to move the whole body is not conducive to multi-point orientation, such as battery array sun orientation and communication ground orientation, etc. This maneuvering mode requires numerous actuators on the satellite to coordinate the maneuvering. The patent only directly drives the load, and the platform of the satellite hardly moves, so it basically does not break the orientation of the battery array and the antenna, etc. Even if it breaks the balance of the original platform, the angle of the platform attitude deflection caused by the load maneuvering is much smaller than the angle of the traditional direct maneuvering. The larger the inertia difference between the load and the spacecraft, the smaller the influence of the load attitude maneuvering on the spacecraft, so the angle of the reverse maneuvering required by the antenna and the sailboard and other mechanisms that need to be oriented when applying the invention is much smaller.

[0043] (3) Traditional attitude control method needs flywheel and CMG to control the satellite platform attitude, and the antenna and sailboard on it are equipped with directional mechanism. The load pointing control can be realized by using one product of the application, when the load and sensor sensitive to attitude are located on the moving platform, and the auxiliary equipment such as power system, thermal control system, data transmission system, measurement and control system, which have low attitude requirement, are arranged on the satellite platform. At this time, the attitude requirement of the satellite platform can be relaxed, and even the directional requirement of the antenna and sailboard can be realized by the cooperative movement of their respective driving mechanisms. Therefore, the satellite platform is used as a large inertia basis, the attitude maneuver and stabilization of the load are directly driven by the product of the application, and the antenna and sailboard mechanisms that need to be oriented are cooperatively moved, which can reduce the response speed and precision of the platform attitude control system, reduce the configuration requirement of the attitude control system, and is especially suitable for the rapid development of small and medium-sized satellites.

[0044] (4) The traditional attitude control method relies on the angular momentum exchange of flywheel and other execution mechanisms to drive the whole satellite to rotate. However, the angular momentum exchange rate is slow, and the inertia of the whole satellite is large, so the acceleration of the whole satellite is small, and the starting speed is slow. The load is directly driven by the application, and the rotational inertia of the load is small. Moreover, the bandwidth of the parallel mechanism is high, and the maneuvering speed is fast, so the maneuvering speed of the load can be quickly increased to a high angular speed, and the load attitude can be quickly maneuvered and controlled.

[0045] If the satellite system does not configure the service platform attitude execution mechanism, although the satellite service platform will produce a certain rotation, its angular speed is much slower, and the satellite service platform attitude error only depends on the rotational inertia and the bias angular momentum of the service platform. If the attitude of the service platform is not high, the attitude control can not be performed; if the attitude of the platform is high or the maneuvering angle of the load is large, the attitude control can be performed by using the execution mechanism. Although the maneuvering speed of the satellite platform is slower than that of the load, the platform can follow the attitude maneuvering of the load, and through the asynchronous maneuvering of the load and the satellite platform, the attitude agile maneuvering of the load is realized, the slow maneuvering of the platform is realized, and the activity range of the parallel mechanism is released for the attitude maneuvering of the load. The slow maneuvering of the platform is beneficial to the stable control of the flexible structure such as the solar sailboard, and is easier to realize the rapid stabilization of the satellite platform. It can be seen that the application does not depend on the maneuvering ability of the flywheel or CMG attitude execution mechanism, but can significantly shorten the maneuvering time of the load. Therefore, the application overcomes the low bandwidth and slow speed of the traditional method, and is a truly agile attitude execution mechanism.

[0046] (5) Traditional load attitude is driven by satellite platform attitude control to drive the load attitude movement, to achieve indirect attitude control, its attitude accuracy can not be too high; the magnetic suspension super platform described in this patent has certain attitude adjustment function, and the attitude of the load on the platform follow-up parallel mechanism can release the adjustment range of the load, through the coarse and fine two-stage attitude adjustment, to realize the absolute pointing super-precision of the load.

[0047] (6) This patent adopts a main and passive integrated magnetic suspension structure of permanent magnet and voice coil motor in parallel, which can not only isolate the vibration transmission between the load and the platform, but also can fine-tune the attitude of the load through the voice coil motor, realizing the super-precision and super-stability of the absolute pointing of the load. Unlike the traditional three-super which relies on the main and passive structure form of voice coil motor and diaphragm spring, the physical contact of diaphragm spring will transmit part of the low-frequency vibration; this patent is also different from the traditional double-super which relies on the pure active form of voice coil motor, which needs to be detected and controlled at all times, while this patent can maintain the magnetic suspension state between the load and the platform through less control without actively adjusting the attitude and actively suppressing vibration, and still physically block the transmission of vibration, so it is more energy-saving and efficient.

[0048] (7) Traditional satellites generally actively isolate the vibration for flywheels and CMG actuators, and if the attitude accuracy, stability and quietness of the load are required to be higher, passive isolation can be performed for the load again; although two-stage isolation is achieved, the system is complex and the weight is large. While the parallel mechanism magnetic suspension super platform in this patent itself has two-stage raft isolation effect, that is, the parallel mechanism constitutes passive isolation, and the magnetic suspension super platform constitutes main and passive integrated isolation; and the magnetic suspension static platform has certain mass and moment of inertia, so the vibration of the load can be transmitted to the magnetic suspension static platform through the voice coil motor; thereby realizing the vibration super-station of the load, and there is no sensor and load sensitive to micro-vibration on the static platform, so it is an ideal kinetic energy container. At the same time, the voice coil motor provides force and torque for active vibration control, and can provide certain damping through closed magnetic damping coil when needed (such as during rapid maneuvering), realizing super-precision, super-stability and super-station. It can be seen that this patent is load-target-oriented, and can realize higher attitude super-stability and super-station performance of the load.

[0049] (8) This patent realizes passive magnetic suspension of the load through the repulsive force of the permanent magnet, the closer the distance between the dynamic and static platforms, the greater the repulsive force; when the distance is very close, the repulsive force is also very large, which can play a non-contact limiting role; obviously different from the traditional spring or hard structure limiting, it not only realizes physical isolation, but also realizes the limiting of the dynamic and static platforms, so the structure of this invention is simpler and can effectively prevent collision and impact.

[0050] (9)The application realizes direct driving of load attitude maneuvering and stabilization by using the super platform of the parallel mechanism to borrow power from the spacecraft platform, the force and torque in the maneuvering process are transmitted through the nut screw, the locking of the non-maneuvering branch is realized by using the radial transmission and self-locking of the nut screw, the main torque and load are transmitted to the platform through the screw, and therefore the product has better mechanical stability and anti-mechanical performance. In addition, the parallel mechanism has higher support stiffness and positioning accuracy.

[0051] Specifically, as shown in the figure, Figures 1 to 5 the embodiment of the application provides a passive-active integrated magnetic suspension five-super load platform based on a parallel mechanism, which comprises a parallel mechanism frame 4 and a magnetic suspension super platform 5 connected with each other, the parallel mechanism frame 4 is further connected with a satellite body 3, and the magnetic suspension super platform 5 is further connected with a load 2.

[0052] The parallel mechanism frame 4 comprises a plurality of branch chains, which are used to provide attitude maneuvering capability for the magnetic suspension super platform 5, the magnetic suspension super platform 5 comprises a magnetic suspension vibration isolator 15, a voice coil motor, a magnetic suspension moving platform 18 and magnetic damping, the magnetic suspension moving platform 18 is used to mount the load 2, the voice coil motor is connected with the magnetic suspension moving platform 18 and the parallel mechanism frame 4 respectively, and provides active adjustment of the magnetic suspension moving platform 18 capability, and the magnetic suspension vibration isolator 15 is used to reduce vibration in the moving process.

[0053] In the embodiment, the load 2 can be an optical camera, a radar and a laser communication device and the like effective load 2. An absolute attitude sensor such as a star sensor, a high-dynamic gyroscope and an acceleration sensor is arranged on the load 2. The parallel mechanism frame 4 can be set as a three-branch chain, a four-branch chain and the like multi-branch chain parallel mechanism according to the number of degrees of freedom of agile attitude maneuvering of the satellite load 2 and the like task requirements, and mainly realizes large-range attitude maneuvering of the moving platform and provides large-range super-agile attitude maneuvering capability for the magnetic suspension super platform 5. Among them, the three-branch chain platform "super" platform is as shown in the figure. Figure 3 The platform can realize three-axis maneuvering range superior to ±45°, and the maneuvering range can be further increased through configuration design, and can meet the maneuvering requirements of most loads 2. The magnetic suspension moving platform 18 provides a mounting interface for the load 2 and provides small-range attitude fine adjustment and micro-vibration isolation for the load 2, and creates a super-precision, super-stable and super-quiet working environment for the stable work of the load 2.

[0054] In some embodiments of the application, the parallel mechanism frame 4 comprises a parallel mechanism base 6, a grating code disc 7, a rotary motor 8, a screw 9, a nut 10, a damping rod 11, a hinge 12, a parallel mechanism moving platform 13 and an electric cylinder 14.

[0055] The parallel mechanism frame 4 adopts a 3-PURU / 1-PRU or 3-PURU / 1-RU multi-chain parallel configuration, so that the parallel mechanism frame 4 realizes three-axis rotation freedom and large-angle rotation, the parallel mechanism base 6 is a triangle, and two groups of rotary motors 8 and grating encoders 7 are arranged at three vertices of the triangle, and a lead screw 9 is arranged on each side of the triangle, one end of the lead screw 9 is connected to one rotary motor 8 and grating encoder 7 to control the rotation of the lead screw 9 according to a preset number of turns, one end of a damping rod 11 is threadedly connected to the lead screw 9 through a nut 10, and the other end of the damping rod 11 is connected to a parallel mechanism moving platform 13 through a hinge 12, the parallel mechanism moving platform 13 is connected to a magnetic suspension moving platform 18 through a voice coil motor and a magnetic suspension vibration isolator 15, and an electric cylinder 14 is arranged in the middle of the parallel mechanism base 6.

[0056] The lead screw 9 is driven to rotate by the rotary motor 8, the nut 10 is translated, and the rotation of the parallel mechanism moving platform 13 is realized through the hinge 12, so that the direction of the magnetic suspension super platform 5 in a local area is pointed in any continuous angle, and three-axis large-range attitude maneuvering of the load 2 is realized.

[0057] In the embodiment, the 3-PURU / 1-PRU is described.

[0058] In some embodiments of the application, the damping rod 11 is composed of a spring damper, which is used to passively isolate the satellite platform from high-frequency vibrations.

[0059] In some embodiments of the application, the parallel mechanism frame 4 includes structural damping, which is used to dissipate the energy of local resonance and improve the super-stability and super-static performance of the load 2.

[0060] In some embodiments of the application, the magnetic suspension vibration isolator 15 supports the magnetic suspension moving platform 18 and the parallel mechanism moving platform 13 through repulsive force of a permanent magnet without contact, so as to limit the relative position of the two within a certain range, and form a passive vibration isolation system. When the relative position changes, the repulsive force will automatically return to the vicinity of the equilibrium point, and if the system is completely symmetrically designed, the balance and low stiffness support can be realized with the assistance of active force.

[0061] In some embodiments of the present application, the magnetic suspension vibration isolator 15 comprises a mounting rod 19, a mounting sleeve 20, a first axial permanent magnet 21, a second axial permanent magnet 22, a gap ring 23, an inner radial permanent magnet 24, an outer radial permanent magnet 25, a sleeve 26, and a locking ring 27, the mounting sleeve 20 is internally provided with the sleeve 26, the first axial permanent magnet 21 is arranged in the middle of the sleeve 26, two second axial permanent magnets, two gap rings 23, two inner radial permanent magnets 24, two outer radial permanent magnets 25, and two locking rings 27 are sequentially arranged on both sides of the first axial permanent magnet 21 respectively, the mounting rod 19 is connected with the magnetic suspension moving platform 18, and the mounting sleeve 20 is connected with the parallel mechanism moving platform 13.

[0062] The magnetic suspension vibration isolator 15 supports the magnetic suspension moving platform 18 by using repulsive force of the permanent magnet, and limits the relative position of the magnetic suspension moving platform 18 and the parallel mechanism moving platform 13 within a certain range, so that the system constitutes a passive vibration isolation system, when the relative position changes, the repulsive force will automatically restore to the vicinity of the equilibrium point, and if the system is completely symmetrical in design, the balance and low stiffness support can be realized with the assistance of active force.

[0063] In some embodiments of the present application, the voice coil motor is used to provide 6 degrees of freedom of force and torque.

[0064] In some embodiments of the present application, the axial direction of each voice coil motor is connected in parallel with a displacement sensor, which is used to detect the axial relative position change of the voice coil motor.

[0065] The active magnetic suspension system composed of the voice coil motor can not only adjust the attitude of the upper platform within a certain range, and then realize the pointing super-precision and super-stability of the load 2, but also can control the vibration of the upper platform, and actively transmit the vibration to the lower platform, so as to realize the super-stability of the upper platform, and create a better environment for the load 2.

[0066] The voice coil motor is internally provided with an on-off damping coil, when the coil is closed, a certain passive magnetic damping is provided, and when the coil is disconnected, the damping disappears, so that the system damping is adjusted and controlled.

[0067] In some embodiments of the present application, the stator part of the voice coil motor is fixed to the parallel mechanism moving platform 13, and the rotor part of the voice coil motor is fixed to the magnetic suspension moving platform 18.

[0068] In some embodiments of the present application, the voice coil motor comprises a first voice coil motor 16 and a second voice coil motor 17, the axes of the first voice coil motor 16 and the second voice coil motor 17 are perpendicular, four first voice coil motors 16 are used to control the axial yaw and axial movement of the magnetic suspension moving platform 18, and four second voice coil motors 17 are used to control the translation in two horizontal directions and the rotation around the axial direction.

[0069] Parallel mechanism frame 4 provides passive vibration isolation, which is two-stage series with main-passive integrated magnetic suspension super platform 5, which can adjust the pose of load 2 in two stages, and can attenuate vibration in full frequency band through the two-stage raft, and finally realize the "five super" performance of super-precision, super-stability, super-quietness, super-agility of load 2.

[0070] Please refer to Figure 6 The patent aims at "five super" target and two-stage structure, and adopts a control strategy of taking platform as the main part and load following in the attitude agile maneuvering, and a control strategy of taking load as the main part and platform following in the attitude stability. Through master-slave switching control, different working condition requirements are adapted.

[0071] Relative pose control of load cabin following platform cabin

[0072] The traditional control strategy is to take platform cabin as the main part and load cabin following, that is, the main-passive magnetic suspension super platform only plays a supporting role and does not play an active fine adjustment function of the pose, and the load attitude is completely ensured by the attitude adjustment of the platform cabin, so only the relative pose control is needed according to the relative position information of the moving and static platforms measured by the displacement sensor. That is, the relative pose of the load cabin with respect to the platform cabin estimated by the displacement sensor is used for feedback control, and the moving and static platforms are controlled to the appropriate pose to realize the fixed supporting state; the magnetic bearing stiffness can be improved by modifying the feedback coefficient.

[0073] The attitude motion of the platform cabin is transmitted through the change of the relative position of the magnetic suspension moving and static platforms, the load cabin is controlled to follow the platform cabin motion, the collision of the moving and static platforms is avoided, and the attitude super-agility of the load cabin is realized.

[0074] Absolute pose control of platform cabin following load cabin

[0075] Through the feedback of absolute attitude sensors such as star sensor and gyroscope, the fast and large-range attitude coarse adjustment is realized by using parallel mechanism, and the high-bandwidth and small-range attitude fine adjustment is realized by using active magnetic suspension mechanism such as voice coil motor, the organic combination of coarse and fine absolute attitude control can realize the large-range fast attitude maneuvering of the load, and the high-precision pointing stability of the load, and realize the super-precision, super-stability and super-agility performance of the load attitude.

[0076] Through the passive vibration isolation of parallel mechanism and the two-stage series vibration isolation of main-passive integrated magnetic suspension, the transmission of vibration is reduced, the vibration isolation of satellite platform is realized, and the stiffness of the magnetic suspension mechanism is low, so the isolation effect of micro-vibration is good. At the same time, the voice coil motor can actively control the interference generated by the filter wheel in the camera through the feedback of absolute attitude sensors such as accelerometer, star sensor and gyroscope, so as to realize the super-quietness of the load attitude.

[0077] In summary: 1) The application mode of this patent breaks through the traditional attitude control mode, directly drives a smaller load for attitude maneuvering and stabilization, so the maneuvering speed and efficiency are higher, and the configuration requirements of the attitude control system are correspondingly reduced. 2) This patent only drives the load to maneuver, and the platform is almost stationary, so it basically does not break the orientation of the battery array and the antenna, so it also breaks through the traditional load attitude maneuvering, which breaks the attitude stability of the whole satellite, and the on-board solar cell array drive mechanism, antenna drive mechanism, etc. need to be oriented multiple mechanisms to coordinate the maneuvering mode. 3) This patent adopts a two-stage floating raft structure based on a spring-damping passive vibration isolator and a main-passive integrated magnetic suspension structure based on a permanent magnet and a voice coil motor in parallel, which can efficiently isolate the vibration transmission between the load and the platform, and the voice coil motor can also finely adjust the attitude of the load, achieving ultra-precision and ultra-stability of the load pointing, breaking through the traditional single-stage isolation mode. Therefore, this invention targets the load attitude, and is expected to truly achieve the "five super" effect of ultra-precision, ultra-stability, ultra-quietness, and ultra-agility of the load attitude.

[0078] (1) Application scenario example of parallel mechanism super platform

[0079] This patent directly targets the attitude ultra-precision, ultra-stability, ultra-quietness, and ultra-agility requirements of the load on satellites and other spacecraft, combines related technologies such as main-passive magnetic suspension, magnetic damping, and parallel mechanisms, and provides a "main-passive integrated magnetic suspension'super' platform based on a parallel mechanism", which realizes "five super" performance through the organic cooperation of the parallel mechanism and the magnetic suspension super platform. That is, the parallel mechanism borrows power and torque from the satellite platform to directly drive the load for rapid attitude maneuvering, achieving large-range rapid attitude maneuvering and stability control of the load; the main-passive integrated magnetic suspension is used to achieve small-range high-precision attitude control of the load, and the coarse and fine two-stage absolute attitude cooperative control can achieve ultra-precision, ultra-stability, ultra-quietness, and ultra-agility of the load; moreover, this patent only drives the load to maneuver, and the platform is almost stationary, so it basically does not break the orientation of the battery array and the antenna. On the other hand, this patent adopts a main-passive two-stage floating raft vibration isolation, and the load side vibration isolation adopts a main-passive integrated magnetic suspension, which realizes complete physical isolation of the dynamic and static platforms in both active and passive states, which is more conducive to vibration isolation. In short, this patent adapts to the current trend of high-precision large-range stabilization and sensitivity or striking of loads.

[0080] As can be seen, this patent product can be used for ultra-quiet test platforms on spacecraft, and can also be used for large-range rapid attitude maneuvering and ultra-precision, ultra-stability, and ultra-quiet pointing of cameras and other loads, and can also be used as an ultra-quiet test platform on spacecraft; it can also be used for rapid high-precision high-stability striking platforms of spaceborne, shipborne, and other laser weapons, and it has strong versatility, wide application fields, and good application prospects. It is especially suitable for the rapid development of small and medium-sized satellites today.

[0081] The patent can be used as a new direction for subsequent load attitude adjusting mechanism development, and is a general load pointing platform with super-precision, super-stability, super-stillness, super-agility and super-wide width, and has high application prospect and application value.

[0082] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A passive-active integrated magnetic suspension five-overload platform based on parallel mechanism, characterized in that, The parallel mechanism frame (4) is connected with a satellite body (3), and the magnetic suspension super platform (5) is connected with a load (2); The parallel mechanism frame (4) comprises a plurality of branch chains for providing the magnetic suspension super platform (5) with attitude maneuvering capability, and the magnetic suspension super platform (5) comprises a magnetic suspension vibration isolator (15), a voice coil motor, a magnetic suspension moving platform (18) for mounting the load (2), and magnetic damping, the voice coil motor is connected with the magnetic suspension moving platform (18) and the parallel mechanism frame (4) respectively, and provides the capability of actively adjusting the magnetic suspension moving platform (18), and the magnetic suspension vibration isolator (15) is used for reducing vibration during movement.

2. The load platform of claim 1, wherein, The parallel mechanism frame (4) comprises a parallel mechanism base (6), a grating scale (7), a rotary motor (8), a lead screw (9), a nut (10), a damping rod (11), a hinge (12), a parallel mechanism moving platform (13), and an electric cylinder (14). The parallel mechanism frame (4) adopts a 3-PURU / 1-PRU or 3-PURU / 1-RU multi-branch chain parallel configuration, so that the parallel mechanism frame (4) realizes three-axis rotation freedom and large-angle rotation, the parallel mechanism base (6) is triangular, two groups of rotary motors (8) and grating scales (7) are arranged at three vertices of the parallel mechanism base (6), and lead screws (9) are arranged on three sides of the parallel mechanism base (6), one end of each of the lead screws (9) is connected with one of the rotary motors (8) and the grating scale (7) to control the rotation of the lead screw (9) according to a preset number of turns, one end of the damping rod (11) is threadedly connected to the lead screw (9) through the nut (10), and the other end of the damping rod (11) is connected to the parallel mechanism moving platform (13) through the hinge (12), the parallel mechanism moving platform (13) is connected to the magnetic suspension moving platform (18) through the voice coil motor and the magnetic suspension vibration isolator (15), and the electric cylinder (14) is arranged in the middle of the parallel mechanism base (6). The rotary motor (8) drives the rotation of the lead screw (9), pushes the nut (10) to translate, and then drives the rotation of the parallel mechanism moving platform (13) through the hinge (12), so that the direction of the magnetic suspension super platform (5) can be pointed in any continuous angle in a local area, and the three-axis large-range attitude maneuvering of the load (2) is realized.

3. The load platform of claim 2, wherein, The damping rod (11) is composed of a spring damper, and is used for passively isolating medium and high frequency vibrations on the satellite platform.

4. The load platform of claim 2, wherein, The parallel mechanism frame (4) comprises structural damping, and the structural damping is used for dissipating the energy of local resonance and improving the super-stable and super-static performance of the load (2).

5. The load platform of claim 2, wherein, The magnetic suspension vibration isolator (15) supports the magnetic suspension moving platform (18) and the parallel mechanism moving platform (13) through repulsion of permanent magnets, so as to limit the relative positions of the two within a certain range, and forms a passive vibration isolation system.

6. The load platform of claim 5, wherein, The magnetic suspension vibration isolator (15) comprises a mounting rod (19), a mounting sleeve (20), a first axial permanent magnet (21), a second axial permanent magnet (22), a magnetic isolation ring (23), an inner radial permanent magnet (24), an outer radial permanent magnet (25), a sleeve (26), and a locking ring (27).

7. The load platform of claim 2, wherein, The voice coil motor is used for providing 6 degrees of freedom force and torque.

8. The load platform of claim 7, wherein, An axial direction of each voice coil motor is connected with a displacement sensor in parallel, which is used for detecting axial relative position change of the voice coil motor.

9. The load platform of claim 7, wherein, A stator part of the voice coil motor is fixed to the parallel mechanism moving platform (13), and a rotor part of the voice coil motor is fixed to the magnetic suspension moving platform (18).

10. The load platform of claim 7, wherein, The voice coil motor comprises a first voice coil motor (16) and a second voice coil motor (17), and the first voice coil motor (16) and the second voice coil motor (17) are perpendicular to each other, wherein four first voice coil motors (16) are used for controlling axial deflection and axial movement of the magnetic suspension moving platform (18), and four second voice coil motors (17) are used for controlling translation in two horizontal directions and rotation around the axial direction.

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