Mechanical falling body device for controlling falling acceleration and falling simulation method

Abstract

The invention relates to a mechanical falling body device for controlling falling acceleration and a falling simulation method, and belongs to the technical field of star soil tests. According to the device, a vertical rail is composed of four steel wire ropes, a mechanical falling body device is arranged on the vertical rail, the mechanical falling body device and the four steel wire ropes are clamped and loosened respectively, and therefore friction force between the mechanical falling body device and the steel wire ropes is changed so as to adjust the acceleration during falling. According to the mechanical falling body device for controlling the falling acceleration, the falling acceleration is controlled based on friction force, and the problem that a low-gravity test for a soil body is difficult is effectively solved. Any 0-1G gravity field environment can be generated, test conditions are provided for tests needing to be carried out under the low-gravity condition, generation of the low-gravity field is more flexible, and the test reproduction difficulty is reduced. According to the simulation method, mechanical tests of a series of star soil in a low-gravity environment are realized, so that comprehensive sounding response of lunar soil in a small-gravity environment and influence action mechanism analysis of a gravity field are realized.

Description

Technical Field

[0001] The invention relates to a mechanical falling device for controlling falling acceleration and a falling simulation method, belonging to the technical field of star soil testing. Background Art

[0002] At present, the main methods for micro / low gravity simulation in aircraft design, space medicine, astronaut training, etc. are gravity compensation methods such as suspension method, robotic arm method, and water flotation method. However, as the stellar soil (such as lunar soil) is a fragmented particle, simply compensating the gravity of the test box where the lunar soil is placed cannot achieve the low gravity simulation of the lunar soil. The low gravity simulation of the lunar soil is more complicated and difficult. The main methods are: 1. Geotechnical centrifuge method. 2. Water seepage force to simulate gravity. 3. Base friction to simulate gravity. 4. Drop tower test.

[0003] Among them, the drop tower method is most similar to the principle of the present invention, the difference is that the drop tower method has strict size and weight restrictions, and it is impossible to carry out geotechnical tests with sand boxes; secondly, the drop tower can only achieve a weightless state of 0g acceleration, and cannot achieve free switching between 1-0g acceleration. Summary of the invention

[0004] Aiming at the defects and problems existing in mechanical tests under the low-gravity environment of stellar soil, the present invention provides a mechanical falling device for controlling falling acceleration and a falling simulation method.

[0005] The present invention adopts the following technical solution:

[0006] The mechanical falling device for controlling falling acceleration described in the present invention comprises a vertical track composed of four steel wires, and a mechanical falling device arranged on the vertical track. The mechanical falling device is clamped and relaxed with the four steel wires respectively, thereby changing the friction between the mechanical falling device and the steel wires to adjust the acceleration during falling. The control equation is as follows:

[0007]

[0008] The friction force provided by the acceleration control system = gravity on the test cabin - wind resistance - complete mass of the test cabin * a.

[0009] The mechanical falling device for controlling falling acceleration of the present invention comprises: a fixed structure, an active clamping mechanism, and a main control motor;

[0010] The fixed structure is used to install the main control motor (2), the active clamping mechanism and the fixed structure are installed in cooperation with each other, and a clamping structure for inserting the steel wire rope is provided between the active clamping mechanism and the fixed structure. The main control motor (2) drives the active clamping mechanism to contract toward the fixed structure, thereby controlling the friction force applied by the clamping structure to the steel wire rope.

[0011] The mechanical falling device for controlling falling acceleration of the present invention comprises a fixed structure including: a first main shaft, a first passive fixed splint, a fixed shaft, a second main shaft, a second passive fixed splint, and a linear bearing;

[0012] The passive fixing splint 1 and the passive fixing splint 2 are arranged parallel to each other, and the dynamic fixing splint 1 and the passive fixing splint 2 are fixed to each other via a fixing shaft;

[0013] The passive fixing splint 2 is provided with a plurality of through holes, the main control motor is fixed between the passive fixing splint 1 and the passive fixing splint 2, and the driving shaft of the main control motor passes through the through holes on the passive fixing splint 2;

[0014] A main shaft 1 and a main shaft 2 are provided between the passive fixing splint 1 and the passive fixing splint 2; one end of the main shaft 1 and the main shaft 2 are fixed on the passive fixing splint 1, and the other end thereof extends from the through hole of the passive fixing splint 2 to the outside;

[0015] The main axis 1 and the main axis 2 are parallel to the fixed axis;

[0016] The active clamping mechanism comprises: an active fixing clamping plate 1, an optical axis, and an active fixing clamping plate 2;

[0017] The active fixing splint 1 and the active fixing splint 2 are arranged parallel to each other, and an optical axis is provided between the active fixing splint 1 and the active fixing splint 2;

[0018] The active fixing splint 1 is provided with a main control motor space hole;

[0019] The active fixing splint 1 and the passive fixing splint 1 in the fixing structure are arranged parallel to each other;

[0020] The active fixing splint 2 and the passive fixing splint 2 in the fixing structure are arranged parallel to each other;

[0021] The active fixing splint 1 and the active fixing splint 2 are both located on the same side of the dynamic fixing splint 1 and the passive fixing splint 2;

[0022] The optical axis passes through the through hole of the passive fixing clamp plate 2 and is fixed to the active fixing clamp plate 2;

[0023] The second main shaft passes through the second active fixed splint.

[0024] The mechanical falling device for controlling falling acceleration of the present invention, the clamping structure comprises a wire rope clamping plate, an active pad, and a passive pad;

[0025] There are two steel wire rope pressure plates, which are arranged parallel to each other; a passive pad is provided between the two steel wire rope pressure plates; the two steel wire rope pressure plates and the passive pad are both located on the end surfaces of the passive fixing clamp plate 1 and the passive fixing clamp plate 2;

[0026] The active pads are both located on the active fixed splint 1 and the active fixed splint 2, and the positions of the active pads and the passive pads are consistent; the active pads are located between the two wire rope pressure plates;

[0027] The wire rope pressure plate is provided with a through hole for the wire rope to pass through; the wire rope is passed between the active pad and the passive pad.

[0028] In the mechanical falling device for controlling falling acceleration described in the present invention, linear bearings are provided on the first main shaft and the second main shaft.

[0029] The falling simulation method of the mechanical falling device for controlling the falling acceleration of the present invention,

[0030] The falling simulation method uses an acceleration sensor, a wind speed sensor, a tension sensor, and a displacement sensor;

[0031] The acceleration sensor is used to detect the falling acceleration of the mechanical falling device in real time and provide feedback data;

[0032] Wind speed sensors are used to monitor external wind speed in order to evaluate and compensate for the effects of wind resistance;

[0033] Install tension sensors at key nodes of the wire rope to measure the force of the wire rope to ensure safety and control accuracy;

[0034] The displacement sensor is used to detect the real-time position of the mechanical falling device;

[0035] The information data obtained by the acceleration sensor, wind speed sensor, tension sensor and displacement sensor are exchanged with the central monitoring system through the wireless communication module;

[0036] The falling simulation method is as follows:

[0037] Startup phase: The controller checks the status of each sensor and servo motor to ensure that the system is in normal working condition; after setting the target acceleration, the controller starts the servo motor to put the wire rope clamp in the initial position and prepare to start falling;

[0038] Falling process: the servo motor adjusts the position of the splint to control the falling acceleration; the acceleration sensor and displacement sensor feedback the actual movement situation, and the wind speed sensor monitors the external environment in real time;

[0039] The PID controller and windage compensation module work together to ensure that the acceleration is stable at the target value.

[0040] Stopping stage: When the predetermined falling distance is reached or the user issues a stop command, the servo motor gradually increases the clamping force, reduces the falling speed, and finally stops the device smoothly.

[0041] The falling simulation method of the mechanical falling device for controlling the falling acceleration of the present invention,

[0042] If the acceleration is detected to exceed the set safety threshold during the falling process, the system will immediately initiate emergency braking, and the servo motor will clamp the wire rope to the maximum extent to prevent the device from falling out of control;

[0043] If the wind speed changes dramatically and the wind resistance changes too much, the controller will increase the clamping force appropriately and send an alarm to the monitoring system through the communication module;

[0044] If the tension sensor detects abnormal tension in the wire rope, the system will automatically stop falling.

[0045] The control strategy of the falling simulation method of the mechanical falling device for controlling the falling acceleration of the present invention includes model predictive control, and the model expression is as follows:

[0046]

[0047] Where: x¨(t+k|t) is the acceleration prediction at the future time t+kt; Fmotor(t+k|t) is the control force prediction at the future time; m(t+k|t) is the mass prediction at the future time, taking into account the load change; Q, R, and P are weighted matrices used to balance the effects of acceleration error, control input, and mass change;

[0048] By minimizing the cost function, the optimal control input F is calculated motor (t) to ensure the acceleration Get as close to the target acceleration a as possible;

[0049] H∞ control is:

[0050]

[0051] Where T zw (s) is the transfer function from disturbance (wind resistance, friction, etc.) to acceleration output;

[0052] By optimizing the control gain matrix K, the impact of disturbances on acceleration can be minimized to ensure that the acceleration is always close to the target a;

[0053] The steps of sliding mode control include:

[0054] Design sliding surface: The sliding surface S(t) can be defined as the difference between the acceleration error and the target acceleration:

[0055]

[0056] Control law design The sliding mode control law is as follows:

[0057] F motor (t) = -Ksgn(S(t))

[0058] Where K is the gain parameter and sgn(S(t)) is the sign function used to guide the system state to slide along the sliding surface.

[0059] Beneficial Effects

[0060] The mechanical falling device for controlling falling acceleration provided by the present invention effectively solves the difficulty of low-gravity testing on soil based on the way of controlling falling acceleration by friction. Any 0-1G gravity field environment can be generated to provide test conditions for various tests under low gravity conditions. Compared with other tests such as drop tower tests, the cost is greatly reduced, the generation of low-gravity fields is more flexible, and the difficulty of test reproduction is reduced.

[0061] The falling simulation method of the mechanical falling device for controlling the falling acceleration provided by the present invention realizes a series of mechanical tests of lunar soil in a low-gravity environment, thereby achieving a more comprehensive analysis of the sounding response of lunar soil in a low-gravity environment and the influence mechanism of the gravity field. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a schematic diagram of the overall structure of the mechanical falling device for controlling falling acceleration of the present invention;

[0063] Figure 2 It is a schematic diagram of the fixed structure of the mechanical falling device for controlling the falling acceleration of the present invention;

[0064] Figure 3 It is a schematic diagram of the active clamping mechanism of the mechanical falling device for controlling the falling acceleration of the present invention;

[0065] Figure 4 It is a schematic diagram of the compression structure of the mechanical falling device for controlling the falling acceleration of the present invention;

[0066] Figure 5 This is a simulation verification test diagram of the drop simulation method of the present invention. DETAILED DESCRIPTION

[0067] In order to make the purpose and technical solution of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0068] like Figure 1 As shown: The present invention is mainly composed of 4 specially designed clamps, 3 sets of optical axes, wire rope clamps, clamps, gaskets and servo motors. The servo motor at the center of the device is driven to realize the function of controlling the magnitude of the falling acceleration of the device. The specific technical solution is:

[0069] The device falls vertically on the track of four steel wire ropes. When falling, the servo motor drives the steel wire rope clamping plate to move closer to or away from another clamping plate to clamp or loosen the steel wire rope, thereby changing the upward friction force provided by the steel wire rope, thereby changing the acceleration of the whole device when falling. The specific formula is:

[0070]

[0071] Friction provided by the acceleration control system = gravity on the test cabin - wind resistance - complete mass of the test cabin * a

[0072] The device can control the acceleration during falling, thereby creating an arbitrary low-gravity state between 0 and 1G, which can be used to conduct a series of experiments in the low-gravity environment of lunar soil.

[0073] A mechanical falling device for controlling falling acceleration, the mechanical falling device comprising: a fixed structure, an active clamping mechanism, and a main control motor 2;

[0074] The fixed structure is used to install the main control motor 2, and the active clamping mechanism and the fixed structure are installed in cooperation with each other. A clamping structure for the wire rope to be inserted is provided between the active clamping mechanism and the fixed structure. The main control motor 2 drives the active clamping mechanism to contract toward the fixed structure, thereby controlling the friction force applied by the clamping structure to the wire rope.

[0075] like Figure 2 As shown: the fixed structure includes: a main shaft 1, a passive fixed splint 4, a fixed shaft 7, a main shaft 8, a passive fixed splint 9, and a linear bearing 12;

[0076] The passive fixed splint 1 4 and the passive fixed splint 2 9 are arranged parallel to each other, and the dynamic fixed splint 1 4 and the passive fixed splint 2 9 are fixed to each other via a fixed shaft 7;

[0077] The passive fixing splint 2 9 is provided with a plurality of through holes, the main control motor 2 is fixed between the passive fixing splint 1 4 and the passive fixing splint 2 9, and the driving shaft of the main control motor 2 passes through the through holes on the passive fixing splint 2 9;

[0078] A spindle 1 and a spindle 2 8 are arranged between the passive fixed splint 1 4 and the passive fixed splint 2 9; one end of the spindle 1 and the spindle 2 8 are fixed on the passive fixed splint 1 4, and the other end thereof extends to the outside from the through hole of the passive fixed splint 2 9; the spindle 1 and the spindle 2 8 are parallel to the fixed axis 7; and linear bearings 12 are arranged on the spindle 1 and the spindle 2 8.

[0079] like Figure 3 As shown: the active clamping mechanism includes: an active fixing clamping plate 1 5, an optical axis 3, and an active fixing clamping plate 2 10;

[0080] The active fixing splint 1 5 and the active fixing splint 2 10 are arranged parallel to each other, and an optical axis 3 is provided between the active fixing splint 1 5 and the active fixing splint 2 10;

[0081] The active fixing clamp plate 1 5 is provided with a main control motor space hole 15;

[0082] The active fixing splint 1 5 and the passive fixing splint 1 4 in the fixing structure are arranged parallel to each other;

[0083] The active fixing splint 2 10 and the passive fixing splint 2 9 in the fixing structure are arranged parallel to each other;

[0084] The active fixing splint 1 5 and the active fixing splint 2 10 are both located on the same side of the dynamic fixing splint 1 4 and the passive fixing splint 2 9;

[0085] The optical axis 3 passes through the through hole of the passive fixing clamp plate 2 9 and is fixed to the active fixing clamp plate 2 10;

[0086] The main shaft 2 8 passes through the active fixed clamping plate 2 10 .

[0087] like Figure 4 As shown: the clamping structure includes a wire rope clamping plate 6, an active pad 13, and a passive pad 14;

[0088] There are two wire rope pressure plates 6, and the two wire rope pressure plates 6 are arranged parallel to each other; a passive pad 14 is provided between the two wire rope pressure plates 6; the two wire rope pressure plates 6 and the passive pad 14 are both located on the end surfaces of the passive fixed splint 1 4 and the passive fixed splint 2 9;

[0089] The active pads 13 are located on the active fixed splint 1 5 and the active fixed splint 2 10, and the positions of the active pads 13 and the passive pads 14 are consistent; the active pads 13 are located between the two wire rope pressure plates 6;

[0090] The wire rope pressing plate 6 is provided with a through hole for the wire rope to pass through; the wire rope is passed between the active pad 13 and the passive pad 14 .

[0091] like Figure 5 As shown: the falling simulation method of the mechanical falling device for controlling the falling acceleration of the present invention, the hardware part includes a servo motor, a sensor module, an actuator and a communication module.

[0092] Servo motor: responsible for adjusting the position of the wire rope clamp and controlling the friction force.

[0093] Clamp and wire rope clamp: driven by a servo motor to clamp or release the wire rope, thereby achieving deceleration control of the device.

[0094] Sensor Module:

[0095] Acceleration sensor: detects the falling acceleration of the device in real time and provides feedback data.

[0096] Wind speed sensor: used to monitor the external wind speed in order to evaluate and compensate for the effects of wind resistance.

[0097] Tension sensor: Installed at the key nodes of the wire rope, used to measure the force of the wire rope to ensure safety and control accuracy.

[0098] Displacement sensor: detects the real-time position of the device and provides displacement feedback to help determine whether the system is operating according to the predetermined path.

[0099] Communication module:

[0100] Wireless communication module: used for data exchange between the controller and the central monitoring system to achieve remote monitoring and operation.

[0101] Real-time data is obtained from each sensor and fused, such as calculating the speed by combining the data of the acceleration sensor and the displacement sensor; the PID controller achieves precise control of the servo motor to ensure the stability of the falling acceleration.

[0102] Wind resistance compensation module: Based on the data provided by the wind speed sensor, the wind resistance is estimated in real time and a compensation signal is generated, which is combined with the acceleration control to form a closed-loop control.

[0103] The control strategy of the present invention is as follows:

[0104] The system adopts a closed-loop control structure with a PID controller as the core to achieve precise control of acceleration.

[0105] The closed-loop control process is as follows:

[0106] 1. Target setting: The user sets the target acceleration through the human-machine interface.

[0107] 2. Sensor feedback: The acceleration sensor obtains the actual acceleration of the device in real time, the displacement sensor obtains displacement data, and the wind speed sensor provides wind resistance information.

[0108] 3. Error calculation: The controller calculates the error between the target acceleration and the actual acceleration in real time.

[0109] 4. PID adjustment: According to the error value, the PID controller generates a control signal to drive the servo motor to make corresponding adjustments.

[0110] 5. Wind resistance compensation: The data from the wind speed sensor is used to estimate the wind resistance and generate a compensation signal, which is combined with the PID control signal to further improve the response accuracy of the system.

[0111] The wind resistance compensation strategy is as follows:

[0112] Wind resistance has a significant effect on the device's falling process, especially when falling over long distances or at high speeds. The control system compensates for wind resistance by following these steps:

[0113] Wind resistance estimation model: The wind resistance is estimated by the classic wind resistance model, where the falling speed is measured in real time and other parameters are constants that are known or determined experimentally.

[0114] Compensation signal generation: The estimated wind resistance is converted into a control demand for the servo motor to offset the effect of wind resistance by increasing the clamping force.

[0115] Real-time dynamic adjustment: According to the real-time changes in wind speed, the wind resistance compensation signal is continuously updated to ensure that the acceleration of the entire falling process remains close to the target value.

[0116] The test process is as follows:

[0117] Startup phase: After the system is started, the controller checks the status of each sensor and servo motor to ensure that the system is in normal working condition. After the user sets the target acceleration, the controller starts the servo motor to put the wire rope clamp in the initial position and prepare to start falling.

[0118] Falling process: The servo motor adjusts the position of the splint to control the falling acceleration. Each sensor works continuously, the acceleration sensor and displacement sensor feedback the actual movement situation, and the wind speed sensor monitors the external environment in real time. The PID controller and wind resistance compensation module work together to ensure that the acceleration is stable at the target value.

[0119] Exceeding the acceleration threshold: If it is detected that the acceleration exceeds the set safety threshold, the system will immediately initiate emergency braking, and the servo motor will clamp the wire rope to the maximum extent to prevent the device from falling out of control.

[0120] Drastic changes in wind resistance: If the wind speed changes dramatically, causing the wind resistance to change too much, the controller will increase the clamping force appropriately and send an alarm to the monitoring system through the communication module.

[0121] Abnormal tension: If the tension sensor detects abnormal tension of the wire rope (for example, too large or too small), the system will automatically stop falling and prompt the user to check.

[0122] Stopping stage: When the predetermined falling distance is reached or the user issues a stop command, the servo motor gradually increases the clamping force, reduces the falling speed, and finally stops the device smoothly.

[0123] The control algorithm of the above experiment is implemented as follows: the control algorithm is written in C language or Python, and real-time control is realized based on RTOS. The PID controller and windage compensation module are implemented as configurable modules so that they can be adjusted according to different experimental requirements.

[0124] Data acquisition and display: Data is transmitted to the computer through the serial communication module or CAN bus, and the real-time operation status is displayed using the host computer software.

[0125] System testing and calibration

[0126] Acceleration control test: Perform multiple experiments at different target accelerations to evaluate control accuracy and response time.

[0127] Verification of wind resistance compensation effect: Verify the effect of the wind resistance compensation module by changing the wind speed and falling speed.

[0128] Repeatability and reliability testing: Repeated testing under different environmental conditions to ensure that the system has sufficient robustness and reliability.

[0129] Control system parameters

[0130] Controlled dynamics equation: For an arbitrary acceleration a (in m / s 2 ), the acceleration of the device is controlled by the control force F applied by the servo motor motor and external disturbances (wind resistance, friction, etc.). Assuming the mass of the device is m, its equation of motion is:

[0131]

[0132] in: is the acceleration of the device; F motor (t) is the control force generated by the motor; F ext (t) is the external disturbance force (such as wind resistance, friction, etc.).

[0133] The goal is to make the acceleration Always close to the set target acceleration a.

[0134] Target acceleration a: is set according to the task requirements and can range from 0G to 1G, that is:

[0135] a∈[0,g] where g≈9.8m / s 2

[0136] That is, the target acceleration a ranges from 0 to 9.8 m / s 2 Any value in between.

[0137]

[0138] in: is the acceleration of the device; F motor (t) is the control force generated by the motor; F ext (t) is the external disturbance force (such as wind resistance, friction, etc.).

[0139] External disturbances include wind resistance and mechanical friction. Wind resistance F wind Depends on the speed v, according to the previous model:

[0140]

[0141] The effects of friction and wear can be represented by a decreasing attenuation factor η(t):

[0142] F motor (t) = η(t)F motor,ideal (t)

[0143] Impact of mission payload:

[0144] In practical applications, the mission load (i.e., the total mass of the device) may change. Changes in mission load will affect the inertia of the device, thereby affecting the control of acceleration. Assuming that the change in load is Δm(t), the mass of the device is m(t) = m0 + Δm(t), where m0 is the initial mass and Δm(t) is the load that changes over time.

[0145] The acceleration equation for the device should be adjusted for the change in mass:

[0146]

[0147] Comprehensive control ideas:

[0148] In order to cope with the influence of different acceleration a, task load changes and inertia, the following control strategy is adopted:

[0149] Model Predictive Control (MPC): used to optimize control inputs to ensure the acceleration of the device Always keep near the target acceleration a.

[0150] Robust control (H∞, sliding mode control): used to deal with external disturbances (such as wind speed changes, friction, etc.) and system uncertainties.

[0151] Real-time adjustment of mass and inertia compensation: Compensate for changes in inertia by dynamically adjusting control inputs as mission payload changes are considered.

[0152] Model Predictive Control (MPC) Design:

[0153] MPC minimizes the acceleration error by predicting future acceleration and optimizing control input. For any acceleration a, the MPC cost function can be expanded to:

[0154]

[0155] Where: x¨(t+k|t) is the acceleration prediction at the future time t+kt; Fmotor(t+k|t) is the control force prediction at the future time; m(t+k|t) is the mass prediction at the future time, taking into account the load change; Q, R, and P are weighted matrices used to balance the effects of acceleration error, control input, and mass change. MPC calculates the optimal control input F by minimizing the cost function. motor (t) to ensure the acceleration Get as close to the target acceleration a as possible.

[0156] Predictive Models: For MPC optimization, the dynamic model of the system needs to include the effects of external disturbances and quality changes, such as:

[0157]

[0158] Robust control design (H∞ control):

[0159] H∞ control can further enhance the robustness of the system to the uncertainty of wind resistance, friction and mass change. Its optimization goal is to minimize the system's response to disturbances and keep the acceleration stable under disturbances and uncertainties. The design of H∞ control is as follows:

[0160]

[0161] Where T zw (s) is the transfer function from disturbance (wind resistance, friction, etc.) to acceleration output. By optimizing the control gain matrix K, the effect of disturbance on acceleration can be minimized to ensure that the acceleration is always close to the target a.

[0162] Sliding mode control (SMC): Sliding mode control can provide strong robustness in the face of large external disturbances (such as rapid changes in wind speed, sudden changes in load, etc.). The design steps of sliding mode control are as follows:

[0163] Design sliding surface: The sliding surface S(t) can be defined as the difference between the acceleration error and the target acceleration:

[0164]

[0165] Control law design: The sliding mode control law is as follows:

[0166] F motor (t) = -Ksgn(S(t))

[0167] Where K is the gain parameter and sgn(S(t)) is the sign function used to guide the system state to slide along the sliding surface.

[0168] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A mechanical falling device for controlling falling acceleration, characterized in that: It includes a vertical track composed of four steel wires and a mechanical falling device arranged on the vertical track. The mechanical falling device is clamped and relaxed with the four steel wires respectively, thereby changing the friction between the mechanical falling device and the steel wires to adjust the acceleration during falling. The control equation is as follows: The friction force provided by the acceleration control system = gravity on the test cabin - wind resistance - complete mass of the test cabin * a.

2. The mechanical falling device for controlling falling acceleration according to claim 1, characterized in that: The mechanical falling device comprises: a fixed structure, an active clamping mechanism, and a main control motor (2); The fixed structure is used to install the main control motor (2), the active clamping mechanism and the fixed structure are installed in cooperation with each other, and a clamping structure for inserting the steel wire rope is provided between the active clamping mechanism and the fixed structure. The main control motor (2) drives the active clamping mechanism to contract toward the fixed structure, thereby controlling the friction force applied by the clamping structure to the steel wire rope.

3. The mechanical falling device for controlling falling acceleration according to claim 2, characterized in that: The fixed structure comprises: a main shaft 1 (1), a passive fixed splint 1 (4), a fixed shaft (7), a main shaft 2 (8), a passive fixed splint 2 (9), and a linear bearing (12); The passive fixing splint 1 (4) and the passive fixing splint 2 (9) are arranged parallel to each other, and the dynamic fixing splint 1 (4) and the passive fixing splint 2 (9) are fixed to each other via a fixing shaft (7); The passive fixing clamp plate 2 (9) is provided with a plurality of through holes, the main control motor (2) is fixed between the passive fixing clamp plate 1 (4) and the passive fixing clamp plate 2 (9), and the driving shaft of the main control motor (2) passes through the through holes on the passive fixing clamp plate 2 (9); A main shaft 1 (1) and a main shaft 2 (8) are provided between the passive fixing splint 1 (4) and the passive fixing splint 2 (9); one end of the main shaft 1 (1) and the main shaft 2 (8) are fixed on the passive fixing splint 1 (4), and the other end thereof extends from the through hole of the passive fixing splint 2 (9) to the outside; The main axis 1 (1), the main axis 2 (8) and the fixed axis (7) are parallel; The active clamping mechanism comprises: an active fixing clamping plate 1 (5), an optical axis (3), and an active fixing clamping plate 2 (10); The active fixing clamp plate 1 (5) and the active fixing clamp plate 2 (10) are arranged parallel to each other, and an optical axis (3) is provided between the active fixing clamp plate 1 (5) and the active fixing clamp plate 2 (10); The active fixing clamp plate 1 (5) is provided with a main control motor space hole (15); The active fixing splint 1 (5) and the passive fixing splint 1 (4) in the fixing structure are arranged parallel to each other; The active fixing clamp plate 2 (10) and the passive fixing clamp plate 2 (9) in the fixing structure are arranged parallel to each other; The active fixing splint 1 (5) and the active fixing splint 2 (10) are both located on the same side of the dynamic fixing splint 1 (4) and the passive fixing splint 2 (9); The optical axis (3) passes through the through hole of the passive fixing clamp plate 2 (9) and is fixed to the active fixing clamp plate 2 (10); The second main shaft (8) passes through the second active fixing clamping plate (10).

4. The mechanical falling device for controlling falling acceleration according to claim 2 or 3, characterized in that: The clamping structure comprises a wire rope clamping plate (6), an active pad (13), and a passive pad (14); There are two steel wire rope pressure plates (6), and the two steel wire rope pressure plates (6) are arranged parallel to each other; a passive pad (14) is provided between the two steel wire rope pressure plates (6); the two steel wire rope pressure plates (6) and the passive pad (14) are both located on the end surfaces of the passive fixing clamp plate 1 (4) and the passive fixing clamp plate 2 (9); The active pads (13) are both located on the active fixed splint 1 (5) and the active fixed splint 2 (10), and the positions of the active pads (13) and the passive pads (14) are consistent; the active pads (13) are located between the two wire rope pressure plates (6); The wire rope pressure plate (6) is provided with a through hole for the wire rope to pass through; the wire rope is passed between the active pad (13) and the passive pad (14).

5. The mechanical falling device for controlling falling acceleration according to claim 3, characterized in that: The main shaft one (1) and the main shaft two (8) are both provided with linear bearings (12).

6. A method for simulating the falling of a mechanical falling device for controlling falling acceleration according to any one of claims 1 to 5, characterized in that: The falling simulation method uses an acceleration sensor, a wind speed sensor, a tension sensor, and a displacement sensor; The acceleration sensor is used to detect the falling acceleration of the mechanical falling device in real time and provide feedback data; Wind speed sensors are used to monitor external wind speed to evaluate and compensate for the effects of wind resistance; Install tension sensors at key nodes of the wire rope to measure the force of the wire rope to ensure safety and control accuracy; The displacement sensor is used to detect the real-time position of the mechanical falling device; The information data obtained by the acceleration sensor, wind speed sensor, tension sensor and displacement sensor are exchanged with the central monitoring system through the wireless communication module; The falling simulation method is as follows: Startup phase: The controller checks the status of each sensor and servo motor to ensure that the system is in normal working condition; after setting the target acceleration, the controller starts the servo motor to put the wire rope clamp in the initial position and prepare to start falling; Falling process: the servo motor adjusts the position of the splint to control the falling acceleration; the acceleration sensor and displacement sensor feedback the actual movement situation, and the wind speed sensor monitors the external environment in real time; Stopping stage: When the predetermined falling distance is reached or the user issues a stop command, the servo motor gradually increases the clamping force, reduces the falling speed, and finally stops the device smoothly.

7. The method for simulating the falling of a mechanical falling device for controlling falling acceleration according to claim 6, characterized in that: If the acceleration is detected to exceed the set safety threshold during the falling process, the system will immediately initiate emergency braking, and the servo motor will clamp the wire rope to the maximum extent to prevent the device from falling out of control; If the wind speed changes dramatically and the wind resistance changes too much, the controller will increase the clamping force appropriately and send an alarm to the monitoring system through the communication module; If the tension sensor detects abnormal tension in the wire rope, the system will automatically stop falling.

8. The method for simulating the falling of a mechanical falling device for controlling falling acceleration according to claim 6, characterized in that: The control strategy includes model predictive control, and the model expression is as follows: Where: x¨(t+k|t) is the acceleration prediction at the future time t+kt; Fmotor(t+k|t) is the control force prediction at the future time; m(t+k|t) is the mass prediction at the future time, taking into account the load change; Q, R, and P are weighted matrices used to balance the effects of acceleration error, control input, and mass change; By minimizing the cost function, the optimal control input F is calculated motor (t) to ensure the acceleration Get as close to the target acceleration a as possible; H∞ control is: Where T zw (s) is the transfer function from disturbance (wind resistance, friction, etc.) to acceleration output; By optimizing the control gain matrix K, the impact of disturbances on acceleration can be minimized to ensure that the acceleration is always close to the target a; The steps of sliding mode control include: Design sliding surface: The sliding surface S(t) can be defined as the difference between the acceleration error and the target acceleration: Control law design The sliding mode control law is as follows: F motor (t)=-Ksgn(S(t)) Where K is the gain parameter and sgn(S(t)) is the sign function used to guide the system state to slide along the sliding surface.

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