A large flexible retractable antenna simulated zero-gravity synchronous suspension system

Abstract

The present invention discloses a large-scale flexible retractable antenna simulated zero-gravity synchronous suspension system, which belongs to the field of antenna lifting technology and includes a lifting steel frame, a lifting mechanism, and a control component; the lifting steel frame is provided with five lifting points, wherein the main lifting point is located in the center, and the remaining four lifting points are auxiliary lifting points, and the four auxiliary lifting points are arranged in a square around the main lifting point and are evenly distributed on the same circumference; the lifting mechanism includes five electric hoists, and each of the electric hoists is provided on a corresponding lifting point in a one-to-one correspondence. The present invention sets five lifting points and uses electric hoists to perform lifting and lowering actions, combined with a PLC control component, to achieve synchronous lifting and lowering of a large-scale flexible retractable antenna, greatly improving work efficiency; at the same time, the infrared laser rangefinder is used to accurately reflect the displacement size of each lifting point, and immediately reflect the synchronization accuracy difference between the lifting points. The actual synchronization accuracy is high, and it is worthy of being promoted and used.

Description

Technical Field

[0001] The present invention relates to the technical field of antenna hoisting, and in particular to a large-scale flexible retractable antenna simulated zero-gravity synchronous suspension system. Background Art

[0002] An antenna is a transducer that converts guided waves propagating along a transmission line into electromagnetic waves propagating in an unbounded medium (usually free space), or vice versa. It is a component used in radio equipment to transmit or receive electromagnetic waves. Engineering systems such as radio communications, broadcasting, television, radar, navigation, electronic countermeasures, remote sensing, and radio astronomy that utilize electromagnetic waves to transmit information rely on antennas. Furthermore, antennas are also required for non-signal energy radiation when transmitting energy using electromagnetic waves. Antennas are generally reversible, meaning the same antenna can be used as both a transmitting and receiving antenna. The basic characteristic parameters of the same antenna for both transmission and reception are the same.

[0003] Large flexible retractable antennas are one of many types of antennas. When hoisting such antennas, existing hoisting devices struggle to synchronize the lifting of all antenna components, which can easily cause the antenna array to shift position. This requires re-adjustment after lifting, which is time-consuming and labor-intensive, resulting in low efficiency. Therefore, a simulated zero-gravity synchronous suspension system for large flexible retractable antennas is proposed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to solve the problem that the existing antenna lifting device is difficult to achieve synchronous lifting of various parts of the antenna equipment, and provides a large-scale flexible retractable antenna simulated zero-gravity synchronous suspension system.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions. The present invention includes a lifting steel frame, a lifting mechanism, and a control component; five lifting points are provided on the lifting steel frame, of which the one located in the center is the main lifting point, and the remaining four lifting points are auxiliary lifting points. The four auxiliary lifting points are arranged in a square around the main lifting point and are evenly distributed on the same circumference; the lifting mechanism includes five electric hoists, and each of the electric hoists is arranged one by one on a corresponding lifting point; the control component includes a frequency converter, a PLC, and a touch control module. Each of the electric hoists is electrically connected to the PLC through the frequency converter, and the touch control module is electrically connected to the PLC.

[0006] Furthermore, the lifting steel frame includes four supporting legs, two main beams, auxiliary lifting beams, and two connecting beams. The four supporting legs are respectively arranged in pairs at the two ends of the two main beams. The two main beams are arranged in parallel. The four auxiliary lifting points are symmetrically arranged in pairs on the two main beams. The auxiliary lifting beam is arranged in the middle between the two main beams. The main lifting point is arranged on the auxiliary lifting beam. The two connecting beams are symmetrically arranged on both sides of the auxiliary lifting beam, and both ends are respectively connected to the two main beams.

[0007] Furthermore, the main beam and the supporting legs are both hollow structures.

[0008] Furthermore, the cross section of the supporting leg is a variable cross section, and the cross section size gradually decreases from top to bottom.

[0009] Furthermore, each of the electric hoists includes a motor, a rope reel, a hook, and a wire rope. The hook is connected to the rope reel through the wire rope, and the rope reel is connected to the output shaft of the motor.

[0010] Furthermore, the wire rope is wound in a single-layer tight manner, and a rope groove is provided on the rope winding drum. The winding radius of the wire rope is the same and fixed during the ascending or descending process.

[0011] Furthermore, the control component further includes a speed measurement module, which is an encoder. The encoder is connected to the output shaft of the motor and is also electrically connected to the PLC and the frequency converter.

[0012] Furthermore, the control component also includes a height measurement module, which includes an infrared laser rangefinder and a corresponding laser reflector. The infrared laser rangefinder is electrically connected to the PLC. Each of the infrared laser rangefinders is arranged on the lifting steel frame and correspondingly arranged next to each of the electric hoists. The laser reflector is arranged at a corresponding position on the suspension medium frame arranged below the infrared laser rangefinder.

[0013] Furthermore, the suspension medium frame is connected to each of the hooks via a synchronous steel wire, and the suspension medium frame is connected to the reflecting surface of the large flexible retractable antenna via a synchronous rope.

[0014] Compared with the existing technology, the present invention has the following advantages: the large-scale flexible retractable antenna simulates a zero-gravity synchronous suspension system, and through the provision of five hanging points, an electric hoist is used for lifting and lowering. In combination with a PLC control component, the large-scale flexible retractable antenna can be raised and lowered synchronously, greatly improving work efficiency; at the same time, an infrared laser rangefinder is used to accurately reflect the displacement size of each hanging point, and the synchronization accuracy difference between the hanging points is immediately reflected. The actual synchronization accuracy is high, and it is worthy of promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the suspension state of the simulated zero-gravity synchronous suspension system in the second embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the principle of the control component in the second embodiment of the present invention;

[0017] Figure 3 It is a schematic diagram of the working principle of the second embodiment of the present invention.

[0018] Figure 1 Middle: 1. Lifting steel frame; 11. Main lifting point; 12. Auxiliary lifting point; 2. Suspension medium frame; 3. Ground antenna equipment to be lifted (large flexible high storage ratio satellite-borne antenna); 4. Suspension steel cable; 5. Suspension rope; 6. Electric hoist (including infrared detection point); 7. Laser reflector; 8. Removable support legs. DETAILED DESCRIPTION

[0019] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process. However, the protection scope of the present invention is not limited to the following embodiment.

[0020] Example 1

[0021] This embodiment provides a technical solution: a large-scale flexible retractable antenna simulated zero-gravity synchronous suspension system, comprising a lifting steel frame, a lifting mechanism, and a control component; the lifting steel frame is provided with five lifting points, wherein the central one is a main lifting point, and the remaining four lifting points are auxiliary lifting points, and the four auxiliary lifting points are arranged in a square around the main lifting point and are evenly distributed on the same circumference; the lifting mechanism comprises five electric hoists, and each of the electric hoists is arranged one by one on a corresponding lifting point; the control component comprises a frequency converter, a PLC, and a touch control module, and each of the electric hoists is electrically connected to the PLC via the frequency converter, and the touch control module is electrically connected to the PLC.

[0022] In this embodiment, the lifting steel frame includes four supporting legs, two main beams, auxiliary lifting beams, and two connecting beams. The four supporting legs are respectively arranged in pairs at the two ends of the two main beams. The two main beams are arranged in parallel. The four auxiliary lifting points are symmetrically arranged in pairs on the two main beams. The auxiliary lifting beam is arranged in the middle between the two main beams. The main lifting point is arranged on the auxiliary lifting beam. The two connecting beams are symmetrically arranged on both sides of the auxiliary lifting beam, and both ends are respectively connected to the two main beams.

[0023] In this embodiment, the main beam and the supporting legs are both hollow structures.

[0024] In this embodiment, the cross section of the supporting leg is a variable cross section, and the cross section size gradually decreases from top to bottom.

[0025] In this embodiment, each of the electric hoists includes a motor, a rope drum, a hook, and a wire rope. The hook is connected to the rope drum via the wire rope, and the rope drum is connected to the output shaft of the motor.

[0026] In this embodiment, the wire rope is wound in a single-layer tight manner, and a rope groove is provided on the rope winding drum. The winding radius of the wire rope is the same and fixed during the ascending or descending process.

[0027] In this embodiment, the control component further includes a speed measurement module, which is an encoder. The encoder is connected to the output shaft of the motor and is also electrically connected to the PLC and the frequency converter.

[0028] In this embodiment, the control component also includes a height measurement module, which includes an infrared laser rangefinder and a corresponding laser reflector. The infrared laser rangefinder is electrically connected to the PLC. Each of the infrared laser rangefinders is arranged on the lifting steel frame and is correspondingly arranged next to each of the electric hoists. The laser reflector is arranged at a corresponding position on the suspension medium frame arranged below the infrared laser rangefinder.

[0029] In this embodiment, the suspension medium frame is connected to each of the hooks via a synchronous steel wire, and the suspension medium frame is connected to the reflecting surface of the large flexible retractable antenna via a synchronous rope.

[0030] Example 2

[0031] This embodiment provides a technical solution: a large-scale flexible retractable antenna simulated weightless synchronous suspension system, including a lifting steel frame, a lifting mechanism, and a control component. The lifting steel frame is set on the ground, and the lifting mechanism is installed on the lifting steel frame. The lifting steel frame is connected to the ground antenna equipment to be lifted through the lifting mechanism, and the control component is electrically connected to the lifting mechanism.

[0032] like Figure 1 Figure 1 shows the overall structure of the lifting steel frame in this embodiment. In this embodiment, the lifting steel frame 1 is provided with five lifting points, of which the center one is the main lifting point 1, with a lifting capacity of 10t. The remaining four are auxiliary lifting points 12, and the maximum load of the lifting steel frame 1 is 10t. The bottom of the lifting steel frame 1 is 18m above the ground. The main lifting point 11 has a load capacity of 10t, and the other four auxiliary lifting points 12 each have a lifting capacity of 3t.

[0033] The main lifting point 11 is in the center, and the four auxiliary lifting points 12 are arranged in a square around the main lifting point, evenly distributed on a circle with a diameter of 20.88m. The distance between two adjacent auxiliary lifting points 12 is 14.77m. (The five lifting points designed in this spatial position ensure structural performance and low structural complexity while meeting lifting requirements with low weight and small size.)

[0034] The lifting steel frame includes supporting legs, main beams, auxiliary lifting beams and connecting beams;

[0035] The outriggers are welded into a box-shaped structure using steel plates. The cross-section of the outriggers is variable, and based on the structural stress characteristics, they are larger at the top and smaller at the bottom. The lower connecting plate is fixed to the concrete foundation (ground) via removable anchor bolts. The upper connecting plate is connected to the main beam via high-strength bolts. The main material of the outriggers is Q345B.

[0036] The main beam is welded into a box-shaped structure with stable structure and strong load-bearing capacity. It is designed according to the structure of large flexible retractable antenna (ground antenna equipment to be hoisted). Two auxiliary lifting points are symmetrically set under the main beam. The load-bearing capacity of each auxiliary lifting point is 3t. The main beam is mainly made of Q345B.

[0037] An auxiliary hanging beam is set between the two main beams, and a main hanging point is set on the auxiliary hanging beam in the middle of the span. The main hanging point has a load-bearing capacity of 10t, which can bear the entire weight of the large flexible retractable antenna. According to the structure of the large flexible retractable antenna, two connecting beams are set on both sides between the two main beams. The main material of the connecting beam is Q345B.

[0038] The five corresponding lifting points adopt a closed ring structure, and the inner ring diameter ensures that the lifting system can hang the ground antenna equipment to be lifted.

[0039] In this embodiment, fixed double-rope electric hoists are installed at each lifting point to achieve lifting and lowering. The five electric hoists constitute the lifting mechanism in this embodiment. During lifting, the five electric hoists lift simultaneously, and each lifting point has single-action and linkage functions to achieve five-point synchronous lifting and single-point fine-tuning capabilities.

[0040] In this embodiment, five electric hoists are hoisted simultaneously and synchronously controlled, so that the large flexible retractable antenna rises synchronously without jitter during the rising process.

[0041] Lifting mechanism speed:

[0042] Hoisting speed: hoisting speed of main lifting point 0.07~0.7m / min;

[0043] Auxiliary lifting point lifting speed 0.08~0.8m / min;

[0044] The lifting height is 16m;

[0045] Lifting mechanism motor power:

[0046] Main lifting point 1.5KW (one unit), auxiliary lifting point 0.4KW / unit (four units);

[0047] The electric hoist motor adopts ZD type conical rotor brake motor.

[0048] Control method: touch screen control + button control.

[0049] like Figure 2 The figure below is a schematic diagram of the control assembly in this embodiment. In this embodiment, the control assembly utilizes program-based automatic control, with hardware implemented using a Yaskawa H1000 series high-performance vector inverter, a Siemens PLC (programmable logic controller), and a touch screen (human-machine interface). The PLC's human-machine interface is open and user-friendly, and includes tracking capabilities for user management and monitoring of the suspension operation status. The control assembly monitors the position and status of the five suspension points in real time, as well as providing alarms, displays, and logs when operational faults occur. The control assembly incorporates safety protection mechanisms such as overload protection, limit protection, power failure protection, and misoperation protection.

[0050] An encoder is installed on the output shaft of each electric hoist motor, forming a closed-loop control loop with the frequency converter; the lifting speed is regulated by a high-performance vector frequency converter; the lifting steel frame is equipped with a positioning sensor and upper and lower limit switches, and the encoder participates in the calculation of the moving distance. The lifting height is displayed by an infrared laser rangefinder on the lifting point (each infrared laser rangefinder is installed next to the hoist, and a reflective plate is installed at the corresponding position on the suspension medium frame to measure the lifting height of each point on the suspension medium frame in real time). The control component instantly corrects the lifting speed and lifting height, and a high-performance controller is used to achieve rapid positioning of the lifting action, ensuring precise control and no shaking during the lifting process.

[0051] During lifting, the lifting height, speed and position information of each lifting point can be displayed in real time on the touch screen. When it is detected that the height difference between any two lifting points reaches 10mm, the synchronous lifting function will automatically stop and the manual function will be switched to the single-point fine-tuning function. The error value of each lifting point will be entered on the touch screen. After manually leveling the height of the five lifting points, the function will be switched to the synchronous function to continue lifting.

[0052] In this embodiment, according to the plane projection size of the five suspension points and the deployment range of the zero-gravity hanger, a lifting steel frame with a structural span of 40 meters, a net height of 18 meters and five central suspension points is adopted to meet the design input requirements.

[0053] In this example, the strength and stiffness of the entire steel frame of a 10-ton suspension system were calculated using the large-scale, general-purpose finite element analysis program ANSYS WORKBENCH, based on the structural design requirements of the "Code for Design of Steel Structures" (GB50017-2003), the "Code for Design of Cranes" (GB3811-2008), and the "General Gantry Crane" (GB / T14406-2011). The results show that the strength and stiffness of the hoisting steel frame meet the requirements of these codes.

[0054] The technical performance parameters of the lifting steel frame are as follows:

[0055] Working level: A3;

[0056] Main structural material: Q345B;

[0057] Allowable stress [σ] = 345 / 1.5 = 230 MPa;

[0058] Allowable vertical static stiffness [f] = L / 500 = 366000 / 500 = 73.2 mm.

[0059] The shell181 element in ANSYS was used. The total number of elements in the finite element calculation model was 75,850, and the total number of nodes was 82,501. Under the rated load, the maximum stress of the structure was 93.057 MPa, located at the connection between the main beam and the outrigger. This location was affected by the support force of the outrigger, resulting in stress concentration. Therefore, the stress at this location was greater than the theoretical maximum stress location - the mid-span stress (σ = 82.717 MPa, see Figure 1 ) is large. Except for this connection, the maximum stress of the main beam is at the mid-span.

[0060] The above stress values are less than the allowable stress of Q345 steel 230MPa, so the structural strength meets the requirements.

[0061] The maximum deformation in the vertical displacement results when the electric hoist lifts a load of 10t is 61.094mm.

[0062] The maximum static displacement in the vertical direction at the mid-span is f=61.094mm<[f]=366000 / 500=73.2mm, so the static stiffness meets the requirements.

[0063] The following are the main functional implementation principles of this system:

[0064] The implementation principle of speed control:

[0065] This lifting system uses a vector control method with a speed sensor. The speed sensor vector control inverter has very high static and dynamic performance. Taking the H1000 inverter of Japan's Yaskawa Electric Corporation as an example (Pe = 0.4kW, Ue = 220V), the speed regulation range is as follows: 1:1500 when there is a speed sensor, and 1:200 when there is no speed sensor. The speed regulation range of the former is 7.5 times that of the latter. The reason is that the speed sensor introduced in the vector control provides the real-time speed of the motor, which is generated by the voltage and current sensors after feedback calculation and has high accuracy. The corresponding parameters of the Yaskawa H1000 series can greatly improve the accuracy of speed control after using speed feedback, thereby achieving the purpose of synchronous lifting.

[0066] Principle of calculating lifting height

[0067] In this embodiment, the electric hoist's wire rope is tightly wound in a single layer, with rope grooves on the winding drum. Therefore, the wire rope's winding radius remains constant during ascent or descent. Therefore, the encoder's pulse count per unit time, ΔP, corresponds to the change in height, ΔH, in a proportional relationship: H = A*P, where A is the specific speed ratio. Considering the gear backlash of the reducer, it is necessary to compensate for this backlash when calculating the ascent position. The specific value needs to be measured during commissioning.

[0068] By determining the lead / lag relationship between the A-phase and B-phase pulses output by the encoder and combining them with the PLC's high-speed counting instructions, the pulse direction can be defined. For example, when the A-phase pulse leads the B-phase, it is defined as forward rotation; when the A-phase pulse lags the B-phase, it is defined as reverse rotation. The number of pulses increases during forward rotation and decreases during reverse rotation. Therefore, the current height of the hanging point can be calculated based on the number of encoder pulses.

[0069] Since the encoder's pulse signal has been input into the inverter, in order for the PLC to also obtain the same set of pulses, it is necessary to use the pulse signal monitoring terminal to forward the pulse signal input from the encoder to the inverter and connect it to the high-speed counting terminal of the PLC, so that the PLC can synchronously receive the encoder's pulse signal.

[0070] Implementation principle of position control

[0071] Position control is divided into four steps: acceleration, constant speed, deceleration, and creeping. PLC can calculate T1, T2, T3, and T4 based on the given target speed and the set acceleration and deceleration time, according to the integral relationship between speed and displacement. The process from T3 to T4 is the creeping speed. The motor of the electric hoist moves slowly at a very low speed, and decelerates and stops after approaching the set target displacement.

[0072] Since the crawling speed is constant during operation, the displacement value from the crawling speed to the stop can be calculated, and deceleration can be achieved in advance when the target displacement is about to be reached, thereby achieving precise control of the position, and the control accuracy can reach ±0.1mm.

[0073] like Figure 1 、 3 As shown, the working principle is: the large-scale flexible retractable antenna simulates zero-gravity synchronous suspension system is used for the test and measurement of new large-scale flexible antennas, and can realize the folding and unfolding experiments of flexible antennas. It mainly includes a five-point synchronous lifting steel frame 1, a control system and an auxiliary suspension device. The lifting steel frame 1 is connected to the suspension medium frame 2 through a suspension steel cable 4 (the end of the suspension steel cable 4 connected to the suspension medium frame 2 is dispersed into multiple radial cables and connected to each connection point on the suspension medium frame 2). The suspension medium frame 2 suspends the antenna reflector (large-scale flexible high-storage ratio satellite-borne antenna) through a zero-gravity suspension rope (suspension rope 5). The five electric hoists 6 are controlled by a five-point synchronous control cabinet to realize the synchronous lifting and lowering of the suspension medium frame 2, and an infrared ranging device is used to measure and control the position of the suspension medium frame points in real time, and ensure the lifting safety and lifting accuracy, thereby realizing the antenna simulated zero-gravity testing and measurement.

[0074] It should be noted that the suspension medium frame is used for simulating zero-gravity suspension of flexible antennas. It is set between the flexible antenna and the lifting steel frame, adopts a multi-level branch structure, and uses high-strength ultra-light aluminum to ensure the structural rigidity and installation accuracy requirements. Its diameter is 33m, which puts very high requirements on weight and installation accuracy. The surface accuracy of the antenna under test is required to be less than 5mm, and the structural accuracy of the suspension medium frame is at least less than 1mm. Therefore, during the lifting, it is necessary to ensure the high synchronization of the lifting points. If the lifting cannot be synchronized, it may cause damage to the antenna reflection surface and the suspension medium frame, causing very large economic losses.

[0075] In summary, the large-scale flexible retractable antenna in the above embodiment simulates a zero-gravity synchronous suspension system. By setting five hanging points and using an electric hoist for lifting and lowering, combined with a PLC control component, it is possible to achieve synchronous lifting and lowering of the large-scale flexible retractable antenna, greatly improving work efficiency. At the same time, the infrared laser rangefinder can accurately reflect the displacement size of each hanging point and immediately reflect the synchronization accuracy difference between the hanging points. The actual synchronization accuracy is high, and it is worthy of promotion and use.

[0076] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A large-scale flexible retractable antenna simulated zero-gravity synchronous suspension system, characterized by: It includes a lifting steel frame, a lifting mechanism, and a control component; the lifting steel frame is provided with five lifting points, of which the central one is the main lifting point, and the remaining four lifting points are auxiliary lifting points. The four auxiliary lifting points are arranged in a square around the main lifting point and are evenly distributed on the same circumference; the lifting mechanism includes five electric hoists, each of which is correspondingly arranged on a corresponding lifting point; the control component includes a frequency converter, a PLC, and a touch control module. Each of the electric hoists is electrically connected to the PLC via the frequency converter, and the touch control module is electrically connected to the PLC; Each of the electric hoists comprises a motor, a rope drum, a hook, and a wire rope, wherein the hook is connected to the rope drum via the wire rope, and the rope drum is connected to the output shaft of the motor; The steel wire rope is wound in a single layer and tightly, and a rope groove is provided on the rope winding drum. The winding radius of the steel wire rope is the same and fixed during the ascent or descent process; The control component further includes a speed measurement module, which is an encoder. The encoder is connected to the output shaft of the motor and is also electrically connected to the PLC and the frequency converter. The control assembly further includes a height measurement module, which includes an infrared laser rangefinder and a corresponding laser reflector. The infrared laser rangefinder is electrically connected to the PLC. Each infrared laser rangefinder is disposed on the lifting steel frame and correspondingly disposed next to each electric hoist. The laser reflector is disposed at a corresponding position on the suspension medium frame disposed below the infrared laser rangefinder. The suspension medium frame is connected to each of the hooks via a suspension steel cable, and the suspension medium frame is connected to the reflective surface of the large flexible retractable antenna via a synchronous suspension rope; The lifting steel frame is connected to the suspension medium frame through a suspension steel cable. One end of the suspension steel cable connected to the suspension medium frame is dispersed into multiple radial cables and connected to each connection point on the suspension medium frame. The suspension medium frame adopts a multi-level branch structure with a structural accuracy of at least less than 1mm.

2. The large-scale flexible retractable antenna simulated zero-gravity synchronous suspension system according to claim 1, characterized in that: The lifting steel frame includes four supporting legs, two main beams, an auxiliary lifting beam, and two connecting beams. The four supporting legs are respectively arranged in pairs at the two ends of the two main beams. The two main beams are arranged in parallel. The four auxiliary lifting points are symmetrically arranged in pairs on the two main beams. The auxiliary lifting beam is arranged in the middle between the two main beams. The main lifting point is arranged on the auxiliary lifting beam. The two connecting beams are symmetrically arranged on both sides of the auxiliary lifting beam, and both ends are respectively connected to the two main beams.

3. The large-scale flexible retractable antenna simulated zero-gravity synchronous suspension system according to claim 2, characterized in that: The main beam and the supporting legs are both hollow structures.

4. The large-scale flexible retractable antenna simulated zero-gravity synchronous suspension system according to claim 2, characterized in that: The cross section of the supporting leg is a variable cross section, and the cross section size gradually decreases from top to bottom.

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