Multi-degree-of-freedom lifting system driven by pushing chain and control method

Abstract

The invention belongs to the technical field of lifting devices, and particularly relates to a multi-degree-of-freedom lifting system driven by a pushing chain and a control method. The lifting platform is driven by the four lifting pushing chain devices to vertically move in the Z direction, the lifting platform is driven by the two horizontal pushing chain devices to horizontally move in the X direction, and the lifting platform is driven by the two horizontal pushing chain devices to horizontally move in the Y direction. According to the lifting system, multi-degree-of-freedom movement in the X direction, the Y direction and the Z direction can be achieved, the space occupancy rate is reduced, the running speed is increased, the working efficiency and maintenance convenience are remarkably improved through a modularized system driven by a pushing chain, the adaptive capacity of the lifting system to complex working conditions is enhanced through programming control, the positioning precision of the lifting system is improved, and the working efficiency is improved. Multi-point stop is achieved, the operation stability is remarkably improved, and the service life is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of lifting device technology, specifically relating to a multi-degree-of-freedom lifting system and control method driven by a push chain. Background Technology

[0002] In the field of mechanical lifting system technology, most lifting systems on the market are currently driven by hydraulics, lead screws, traditional chains, belts, etc., which have the following drawbacks: 1. Traditional chain or belt systems have a high initial height and occupy a large space; 2. Hydraulic systems are prone to oil leaks and are difficult to maintain; 3. The lead screw type has slow speed and low work efficiency.

[0003] The push chain is rigid and can maintain a good shape during vertical and horizontal pushing. It has the advantages of simple and stable structure, fast operation speed, large load capacity and small space occupation, and is now widely used in the field of lifting systems.

[0004] In applications such as automobile production lines and automated warehouses, there is a common need for alternating lifting and transport of various workpieces. Traditional drive-type lifting systems suffer from poor stability, large space occupation, and low work efficiency. While push-chain driven lifting systems can effectively solve the problems of space constraints and efficiency bottlenecks, their flexibility and applicable work scenarios still need further expansion. In particular, there is still considerable room for improvement in the coordination and operational stability of multiple push-chain lifting platforms working together. Summary of the Invention

[0005] This invention discloses a multi-degree-of-freedom lifting system and control method driven by a push chain. The system utilizes four lifting push chain devices to drive the lifting platform vertically in the Z-axis, two sets of horizontal push chain devices to drive horizontally in the X-axis, and two sets of horizontal push chain devices to drive horizontally in the Y-axis. This lifting system enables multi-degree-of-freedom movement in the X, Y, and Z directions. The modular system driven by the push chain reduces space occupancy, accelerates operation, significantly improves work efficiency and maintenance convenience, and enhances the system's adaptability to complex working conditions through programmable control. It also improves positioning accuracy, enables multi-point stopping, significantly enhances operational stability, and extends service life.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A push chain driven multi-degree-of-freedom lifting system includes two sets of first linear guides arranged opposite each other along the Y-axis, two sets of second linear guides arranged opposite each other along the X-axis on the two first linear guides, and Z-axis lifting platforms at both ends of the two second linear guides. The two second linear guides move back and forth along the Y-axis on the first linear guides by a first push chain drive mechanism. The four lifting platforms move back and forth along the X-axis on the second linear guides by a second push chain drive mechanism. Each of the four lifting platforms has a bearing platform 101 at its top. The bearing platform moves up and down along the Z-axis by a third push chain drive mechanism. The four synchronously lifting bearing platforms 101 jointly lift the object being pushed, and the spacing between the four bearing platforms along the X and Y axes is adjusted according to the size and center of gravity of the object being pushed.

[0007] Preferably, the lifting platform includes a folding arm structure and a base. The folding arm structure includes a U-shaped mounting base arranged in a side-standing position, a first connecting arm and a second connecting arm symmetrically arranged on the upper and lower sides of the U-shaped mounting base. One end of the first connecting arm and the second connecting arm on the same side is respectively hinged to the U-shaped mounting base, and the other end is respectively hinged to a top connecting seat and a bottom connecting seat. The top connecting seat and the bottom connecting seat have the same structure and are symmetrically arranged. The top end of the top connecting seat is connected to the bearing platform, and the bottom end of the bottom connecting seat is connected to the base. The third push chain drive mechanism is connected between the bearing platform and the base. Its output push chain drives the bearing platform to rise and fall along the Z-axis. The push chain is connected to the bearing platform through a tension and compression sensor.

[0008] Preferably, the base is slidably connected to the top of the second linear guide rail, and the second push chain drive mechanism is located at the end of the second linear guide rail. The push chain output by the mechanism is connected to the base and used to push the lifting platform to move along the X-axis on the second linear guide rail.

[0009] Preferably, the first push chain drive mechanism includes a fixed seat located between the two first linear guides on the same side. The top of the fixed seat is provided with a guide plate along the Y-axis. A push plate is connected to the guide plate by rollers. A push chain device is connected to the outer end of the top of the fixed seat. The push chain head output by the push chain device is fixedly connected to the push plate. Under the drive of the push chain device, the push plate pushes the second linear guide to move along the Y-axis on the first linear guide.

[0010] A control method for a push chain driven multi-degree-of-freedom lifting system includes: control method one and control method two, wherein control method one is used to control the movement of four lifting platforms along the X-axis and Y-axis; and control method two is used to control the movement of the lifting platforms along the Z-axis.

[0011] Preferably, the control method includes: based on the workpiece's dimension D along the X-axis.x and the dimension D along the Y-axis y The system calculates the X and Y distances between the four support platforms during the lifting process, ensuring the workpiece is stably mounted on top of the four platforms. Based on the downward vertical projection of the workpiece's target position, it calculates the initial positions of each lifting platform on the second linear guide rail and the initial positions of the second linear guide rail itself. Then, through a control mechanism, it controls the first and second push chain drive mechanisms to jointly drive the four lifting platforms to their initial positions at the start of lifting. Alternatively, based on the workpiece's target position, during the lifting process, it adjusts the four lifting platforms to move synchronously along the X or Y axis, ensuring the workpiece reaches its target position when lifted to the required height.

[0012] Preferably, the second control method includes: constructing a "one master, multiple slaves" motion control system using an electronic cam (E-Cam) control algorithm via a programmable controller to achieve coordinated operation of the four lifting platforms; specifically including: A virtual master motion axis Axis0 is set as the motion reference axis to provide a reference position signal; the slave motion axes Axis1, Axis2, Axis3, and Axis4 are the four drive motors M in the third push chain drive mechanism of the four lifting platforms. z1 M z2 M z3 M z4 The output shaft; from the motion axis Axis1 via the electronic cam curve Ecam 10 and Ecam 11 Establish motion coupling with the main motion axis Axis0; from the motion axis Axis2, via the electronic cam curve Ecam 20 and Ecam 21 Establish motion coupling with the main motion axis Axis0; from the motion axis Axis3, via the electronic cam curve Ecam 30 and Ecam 31 Establish motion coupling with the main motion axis Axis0; from the motion axis Axis4 via the electronic cam curve Ecam 40 and Ecam 41A motion coupling relationship is established with the main motion axis Axis0. Specifically, the motion coupling relationship between the main motion axis and the slave motion axis is as follows: the motion position of the main motion axis Axis0 corresponds one-to-one with the real-time position of each slave motion axis. The slave motion axes Axis1, Axis2, Axis3, and Axis4 all follow the main motion axis according to the set electronic cam relationship. Since the four slave motion axes share the same main motion axis reference signal, the motion cycle of the four slave axes is always consistent, that is, the four carrying platforms reach the target position at the same time. Alternatively, according to the workpiece size requirements, the point displacement of the electronic cam curve is modified, and each lifting platform reaches a different target position at the same time according to its own electronic cam curve parameters.

[0013] Preferably, the second control method further includes: employing a thrust-position coupling judgment mechanism, and installing tension / compression sensors FS between the push chain heads of the four lifting platforms and the bearing platform. z1 FS z2 FS z3 FS z4 Real-time detection of the pressure F at the head of the push chain device zi Set the upper pressure limit F z0 The lifting platform's drive motor is a servo motor. The actual position P of the lifting platform is obtained through bus communication between the servo motor's servo driver and the control mechanism. ri and instruction position P si Calculate the positional deviation ΔPi=P ri P si Set the upper limit of position deviation ΔP0; when ΔPi>ΔP0, the control mechanism starts dynamic balance adjustment, that is, by changing the position of the lifting platform with excessive position deviation, it compensates for the off-center load and offset; when F zi >F z0 If ΔPi > ΔP0 for t0 seconds, the off-center load protection will be triggered immediately, locking the position of the lifting system.

[0014] Preferably, control method one and control method two work together to enable the four support platforms to be at different heights and positions, so that the four support platforms can adapt to the three-dimensional shape of the workpiece and lift and lower the workpiece.

[0015] The beneficial effects of the push-chain driven multi-degree-of-freedom lifting system and control method of the present invention are as follows: (1) This invention provides two lifting modes for the workpiece: first, the four support platforms are moved to their initial positions, and then the workpiece is lifted vertically to directly reach the target position; or, during the lifting process, the workpiece reaches the target position in the air through the synchronous movement of the four support platforms. Compared with traditional lifting systems, this invention enables the workpiece to move vertically, horizontally, or in a combination of both in the air, greatly expanding the degree of freedom of the lifting platform and further meeting the more complex usage requirements of automated industrial production.

[0016] (2) By setting the target height of each bearing platform, the present invention can perform more flexible and stable lifting control on irregular workpieces, thus making the present invention have a wider range of applications.

[0017] (3) The present invention adopts an electronic cam control algorithm, which improves the positioning accuracy of the lifting system; through the thrust-position coupling judgment mechanism, the position deviation caused by the off-center load can be quickly corrected and the off-center load protection can be realized, ensuring the platform operates smoothly and safely.

[0018] (4) The lifting system of the present invention adopts a modular design. Each module is driven by a push chain, which significantly reduces the initial height and space occupation of the bearing platform, while improving the running speed and the convenience of installation and maintenance, and comprehensively improving production efficiency.

[0019] (5) The lifting system of the present invention has high flexibility and can realize multi-degree-of-freedom movement in the X, Y and Z directions. It can move horizontally in the X and Y directions and has vertical lifting capability in the Z direction. Through the combination of multi-degree-of-freedom movement, it can meet the operation requirements of complex scenarios, adapt to workpieces of various sizes and enhance the stability of operation.

[0020] (6) The lifting system of the present invention can adjust itself when subjected to impact, and realize the automatic adjustment of dynamic force balance when complex parts are unstable. Attached Figure Description

[0021] Figure 1 : Axonometric view of the lifting system of this invention; Figure 2 Top view of the lifting system of this invention; Figure 3 : Structural diagram of the lifting platform of this invention; Figure 4 : A simplified structural diagram of the lifting platform of this invention; Figure 5 : Axonometric drawing of the second linear guide rail of the present invention; Figure 6 : Axonometric view of the first push chain drive mechanism of the present invention; Figure 7 : Control flowchart of this invention; Figure 8: Schematic diagram of the electronic cam control algorithm curve of this invention.

[0022] Marked in the image: 1. Lifting Platform One; 2. Lifting Platform Two; 3. Lifting Platform Three; 4. Lifting Platform Four; 5. Second Push Chain Drive Mechanism A; 6. Second Push Chain Drive Mechanism B; 7. Second Push Chain Drive Mechanism C; 8. Second Push Chain Drive Mechanism D; 9. Second Linear Guide Rail A; 10. First Linear Guide Rail A; 11. Second Linear Guide Rail B; 12. First Linear Guide Rail B; 13. First Push Chain Drive Mechanism A; 14. First Push Chain Drive Mechanism B; 15. Third Push Chain Drive Mechanism A; 16. Third Push Chain Drive Mechanism B; 17. Third Push Chain Drive Mechanism C; 18. Third Push Chain Drive Mechanism D; 19. Tension / Compression Sensor A; 20. Tension / Compression Sensor Force sensor B; 21. Tension / compression sensor C; 22. Tension / compression sensor D; 101. Bearing platform; 102. First connecting arm; 103. Pull rod assembly; 104. U-shaped mounting base; 105. Rotating shaft; 106. Second connecting arm; 107. Base; 108. Third push chain drive mechanism; 109. Top connecting seat; 110. Bottom connecting seat; 111. Pushed object; 901. Slider; 902. Linear guide rail body; 903. Motor connecting plate; 904. Flat push chain device; 1301. Back plate; 1302. Push chain device; 1303. Roller; 1304. Guide rail plate; 1305. Fixed seat; 1306. Push plate. Detailed Implementation

[0023] The following description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0024] The following embodiments can be understood as illustrating a part of the structure or method of the present invention individually, or as combining the embodiments to explain the broader structure or method of the present invention.

[0025] Example 1: A push-chain driven multi-degree-of-freedom lifting system, such as Figure 1 , 2As shown, it includes two sets of first linear guides (10 / 12) arranged opposite each other along the Y-axis, two sets of second linear guides (9, 11) arranged opposite each other along the X-axis on the two first linear guides (10 / 12), and Z-axis lifting platforms (1 / 2 / 3 / 4) located at both ends of the two second linear guides (9, 11). The two second linear guides (9, 11) move back and forth along the Y-axis on the first linear guides (10 / 12) respectively through a first push chain drive mechanism (13 / 14). Four lifting platforms (1 / 2 / 3 / 4) are located at both ends of the second linear guides (9, 11). 2 / 3 / 4) respectively move back and forth along the X-axis on the second linear guide rail (10 / 12) through the second push chain drive mechanism (5 / 6 / 7 / 8). The top of the four lifting platforms (1 / 2 / 3 / 4) is respectively provided with a bearing platform 101. The bearing platform 101 moves up and down along the Z-axis through the third push chain drive mechanism (15 / 16 / 17 / 18). The four synchronously lifting bearing platforms 101 jointly lift the object being pushed, and adjust the spacing of the four bearing platforms along the X and Y axes according to the size and center of gravity of the object being pushed.

[0026] In this embodiment, the push chain device in the first to third push chain drive mechanism is prior art, and can be found in patent CN220131061U "A Meshing Push Chain System". The push chain device of this invention can adopt a push chain that can achieve the relevant functions in the prior art. By moving the second linear guide along the first linear guide, the lifting platform can move along the Y-axis. By moving the lifting platform along the second linear guide, the lifting platform can move along the X-axis. By moving the lifting platform itself along the Z-axis, the carrying platform can move along the Z-axis. Combining the above functions, the lifting system achieves multi-degree-of-freedom adjustment.

[0027] Example 2: like Figure 3 , 4 As shown, the lifting platform includes a folding arm structure and a base 107. The folding arm structure includes a U-shaped mounting base 104 arranged in a side-standing position, a first connecting arm 102 and a second connecting arm 106 symmetrically arranged on the upper and lower sides of the U-shaped mounting base 104. One end of the first connecting arm 102 and the second connecting arm 106 on the same side is hinged to the U-shaped mounting base 104, and the other end is hinged to a top connecting seat 109 and a bottom connecting seat 110, respectively. The top connecting seat 109 and the bottom connecting seat 110 have the same structure and are symmetrically arranged. The top end of the top connecting seat 109 is connected to the bearing platform 101, and the bottom end of the bottom connecting seat 110 is connected to the base 107. The third push chain drive mechanism 108 is connected between the bearing platform 101 and the base 107. Its output push chain drives the bearing platform 101 to rise and fall along the Z-axis. The push chain is connected to the bearing platform 101 through tension and compression sensors (23 / 24 / 25 / 26).

[0028] The detailed structure of the folding arm given in this embodiment can be found in document CN119490148A, "A Foldable Push Chain Lifting Platform," or document CN120463123A, "A Push Chain Synchronous Lifting Platform and Control Method," which describes a folding arm. Lifting platforms implemented with improved folding arms based on these methods are also within the scope of this invention. Driven by the third push chain drive mechanism 108, the folding arm unfolds or closes, achieving a lower initial position and a higher final position for the carrying platform. The folding arm structure and the push chain form an equilateral triangle structure. The folding arm structures at both ends of the same second linear guide rail achieve weight balance, fully ensuring the stability of the push chain running along the Z-axis.

[0029] Example 3: like Figures 1-5 As shown, the base 107 is slidably connected to the top of the second linear guide rail (9, 11), and the second push chain drive mechanism (5 / 6 / 7 / 8) is located at the end of the second linear guide rail (9, 11). The push chain output by the mechanism is connected to the base 107 and used to push the lifting platform (1 / 2 / 3 / 4) to move along the X-axis on the second linear guide rail.

[0030] Example 4: like Figure 1 , 2 As shown in Figure 6, the first push chain drive mechanism includes a fixed base 1305 located in the middle of the same side of the two first linear guides (10 / 12). The top of the fixed base 1305 is provided with a guide plate 1304 along the Y-axis. A push plate 1306 is connected to the guide plate 1304 via a roller 1303. A push chain device 1302 is connected to the outer end of the top of the fixed base 1305. The push chain head output by the push chain device 1302 is fixedly connected to the push plate 1306. Under the drive of the push chain device 1302, the push plate 1306 pushes the second linear guide (9, 11) to move along the Y-axis on the first linear guide.

[0031] Example 5: Based on the above embodiments, this embodiment discloses a control method for a push chain-driven multi-degree-of-freedom lifting system, such as... Figure 7 As shown, it includes: control method one and control method two. Control method one is used to control the movement of four lifting platforms along the X-axis and Y-axis; control method two is used to control the movement of the lifting platforms along the Z-axis.

[0032] Example 6: Specifically, the control method one includes: based on the workpiece's dimension D along the X-axis... x and the dimension D along the Y-axis yThe calculation involves determining the X and Y distances between the four support platforms during the lifting process. The distances between the support platforms must match the length and width dimensions of the workpiece to achieve proper lifting. This ensures the workpiece is stably mounted on the top of the four support platforms. Based on the vertical projection of the workpiece's target position (i.e., the pre-set lifting position), the initial positions of each lifting platform on the second linear guide and the second linear guide itself are calculated. Then, the control mechanism controls the first and second push chain drive mechanisms to jointly drive the four lifting platforms to their initial positions at the start of lifting. Based on this, the workpiece can be vertically lifted to its target position. Alternatively, based on the workpiece's target position, during lifting, the four lifting platforms can be adjusted to move synchronously along the X or Y axis, allowing the workpiece to reach its target position when lifted to the required height. This achieves aerial movement of the workpiece during lifting, moving the target to its target position.

[0033] This embodiment presents two lifting modes for the workpiece: first, the four support platforms are moved to their initial positions, and then the workpiece is vertically lifted to directly reach the target position; or, during the lifting process, the workpiece reaches the target position in mid-air through the synchronous movement of the four support platforms. Compared to traditional lifting systems, this invention allows the workpiece to move vertically, horizontally, or in a combination of both in mid-air, significantly expanding the degrees of freedom of the lifting platform and further meeting the more complex usage requirements of automated industrial production. It is understood that the principle for lowering a workpiece from a high place to a low place is the same.

[0034] Example 7: like Figure 8 As shown, the second control method includes: constructing a "one master, multiple slaves" motion control system using an electronic cam (E-Cam) control algorithm via a programmable controller to achieve coordinated operation of the four lifting platforms; specifically including: A virtual master motion axis Axis0 is set as the motion reference axis to provide a reference position signal; the slave motion axes Axis1, Axis2, Axis3, and Axis4 are the four drive motors M in the third push chain drive mechanism of the four lifting platforms. z1 M z2 M z3 M z4 The output shaft; from the motion axis Axis1 via the electronic cam curve Ecam 10 and Ecam 11 Establish motion coupling with the main motion axis Axis0; from the motion axis Axis2, via the electronic cam curve Ecam 20 and Ecam 21Establish motion coupling with the main motion axis Axis0; from the motion axis Axis3, via the electronic cam curve Ecam 30 and Ecam 31 Establish motion coupling with the main motion axis Axis0; from the motion axis Axis4 via the electronic cam curve Ecam 40 and Ecam 41 A motion coupling relationship is established with the main motion axis Axis0. Specifically, the motion coupling relationship between the main motion axis and the slave motion axis is as follows: the motion position of the main motion axis Axis0 corresponds one-to-one with the real-time position of each slave motion axis. The slave motion axes Axis1, Axis2, Axis3, and Axis4 all follow the main motion axis according to the set electronic cam relationship. Since the four slave motion axes share the same main motion axis reference signal, the motion cycle of the four slave axes is always consistent, that is, the four carrying platforms reach the target position at the same time. Alternatively, according to the workpiece size requirements, the point displacement of the electronic cam curve is modified, and each lifting platform reaches a different target position at the same time according to its own electronic cam curve parameters.

[0035] like Figure 8 As shown, the second control method further includes: employing a thrust-position coupling judgment mechanism, and installing tension and compression sensors FS between the push chain heads of the four lifting platforms and the bearing platform. z1 FS z2 FS z3 FS z4 Real-time detection of the pressure F at the head of the push chain device zi Set the upper pressure limit F z0 The lifting platform's drive motor is a servo motor. The actual position P of the lifting platform is obtained through bus communication between the servo motor's servo driver and the control mechanism. ri and instruction position P si Calculate the positional deviation ΔPi=P ri P si Set the upper limit of position deviation ΔP0; when ΔPi>ΔP0, the control mechanism starts dynamic balance adjustment, that is, by changing the position of the lifting platform with excessive position deviation, it compensates for the off-center load and offset; when F zi >F z0 If ΔPi > ΔP0 for t0 seconds, the off-center load protection will be triggered immediately, locking the position of the lifting system.

[0036] The control method of this invention employs an electronic cam control algorithm, which improves the positioning accuracy of the lifting system. Simultaneously, through a thrust-position coupling judgment mechanism, it can quickly correct positional deviations caused by off-center loading and achieve off-center loading protection, ensuring stable and safe platform operation.

[0037] Understandably, the lifting platform is equipped with tension and compression sensors in the Z direction. When the lifting platform is impacted, the pressure sensor reading increases instantaneously. The control mechanism can automatically adjust the torque through the servo motor, so that when the workpiece with a complex structure is tilted on the bearing platform, the dynamic force balance of each bearing platform can be quickly adjusted. This avoids the problem of the off-center load being aggravated or even causing an accident due to the inability of each bearing platform to adjust the force balance.

[0038] Example 8: like Figure 8 As shown, control method one and control method two work together to position the four support platforms at different heights and locations. This allows the four support platforms to adapt to the three-dimensional shape of the workpiece and to lift and lower it accordingly, ensuring the center of gravity remains balanced during the lifting process and improving the stability of the lifting system. It is understood that many workpieces are irregularly shaped (e.g., the bottom of the workpiece is not flat but has varying heights). By setting the target height for each support platform, this invention allows for more flexible and stable lifting and lowering control of irregularly shaped workpieces, thus broadening its applicability.

[0039] Working principle of the invention: 1. The entire lifting system uses an interlocking push chain system as the drive unit. The push chain consists of two interlocking chains. Each chain is flexible, and under the drive of the sprocket, the two chains interlock to form a rigid "steel column". For details, please refer to patent CN220131061U "An Interlocking Push Chain System".

[0040] 2. The push chain device uses servo motors and reducers as power inputs. The extension length of the push chain is precisely controlled by the encoder at the rear of the servo motor. Each motor can be controlled independently.

[0041] 3. The lifting platform adopts a folding arm structure and is driven by a lifting and pushing chain device to achieve vertical lifting in the Z direction. The Z-direction height can be adjusted through this system.

[0042] 4. The horizontal push chain device uses a roller guide mechanism to drive the lifting platform to achieve horizontal movement in the Y direction through the push plate. This system can be used to adjust the Y-direction spacing between the lifting platforms.

[0043] 5. Guided by the second linear guide rail, the lifting platform moves horizontally in the X direction and is driven by the push chain device. The X-axis spacing between the lifting platforms can be adjusted through this system.

[0044] 6. The lifting system achieves automatic adjustment and overload protection under off-center load conditions through a thrust-position coupling judgment mechanism.

[0045] 7. The lifting system supports differentiated height and position control of four platforms, can synchronously coordinate X, Y and Z three-axis movements, adapt to workpieces of various sizes, ensure the balance of the center of gravity during the lifting process, and improve the stability of system operation.

Claims

1. A push-chain driven multi-degree-of-freedom lifting system, characterized in that: The system includes two sets of first linear guides arranged opposite each other along the Y-axis, two sets of second linear guides arranged opposite each other along the X-axis on the two first linear guides, and Z-axis lifting platforms at both ends of the two second linear guides. The two second linear guides move back and forth along the Y-axis on the first linear guides via a first push chain drive mechanism. The four lifting platforms move back and forth along the X-axis on the second linear guides via a second push chain drive mechanism. Each of the four lifting platforms has a bearing platform 101 at its top. The bearing platforms move up and down along the Z-axis via a third push chain drive mechanism. The four synchronously lifting bearing platforms 101 together lift the object being pushed, and the spacing between the four bearing platforms along the X and Y axes is adjusted according to the size and center of gravity of the object being pushed.

2. The push-chain driven multi-degree-of-freedom lifting system as described in claim 1, characterized in that: The lifting platform includes a folding arm structure and a base. The folding arm structure includes a U-shaped mounting base arranged in a side-standing position, and a first connecting arm and a second connecting arm symmetrically arranged on the upper and lower sides of the U-shaped mounting base. One end of the first connecting arm and the second connecting arm on the same side is respectively hinged to the U-shaped mounting base, and the other end is respectively hinged to a top connecting seat and a bottom connecting seat. The top connecting seat and the bottom connecting seat have the same structure and are symmetrically arranged. The top end of the top connecting seat is connected to the bearing platform, and the bottom end of the bottom connecting seat is connected to the base. The third push chain drive mechanism is connected between the bearing platform and the base. Its output push chain drives the bearing platform to rise and fall along the Z-axis. The push chain is connected to the bearing platform through a tension and compression sensor.

3. The push-chain driven multi-degree-of-freedom lifting system as described in claim 2, characterized in that: The base is slidably connected to the top of the second linear guide rail, and the second push chain drive mechanism is located at the end of the second linear guide rail. Its output push chain is connected to the base and used to push the lifting platform to move along the X-axis on the second linear guide rail.

4. The push-chain driven multi-degree-of-freedom lifting system as described in claim 3, characterized in that: The first push chain drive mechanism includes a fixed seat located between the two first linear guides on the same side. The top of the fixed seat is provided with a guide plate along the Y-axis. A push plate is connected to the guide plate by rollers. A push chain device is connected to the outer end of the top of the fixed seat. The push chain head output by the push chain device is fixedly connected to the push plate. Under the drive of the push chain device, the push plate pushes the second linear guide to move along the Y-axis on the first linear guide.

5. The control method for a push-chain driven multi-degree-of-freedom lifting system as described in claim 4, characterized in that, include: Control method one and control method two are used to control the movement of the four lifting platforms along the X and Y axes; control method two is used to control the movement of the lifting platforms along the Z axis.

6. The control method for a push-chain driven multi-degree-of-freedom lifting system as described in claim 5, characterized in that: The control method one includes: based on the workpiece's dimension D along the X-axis. x and the dimension D along the Y-axis y The system calculates the X and Y distances between the four support platforms during the lifting process, ensuring the workpiece is stably mounted on top of the four platforms. Based on the downward vertical projection of the workpiece's target position, it calculates the initial positions of each lifting platform on the second linear guide rail and the initial positions of the second linear guide rail itself. Then, through a control mechanism, it controls the first and second push chain drive mechanisms to jointly drive the four lifting platforms to their initial positions at the start of lifting. Alternatively, based on the workpiece's target position, during the lifting process, it adjusts the four lifting platforms to move synchronously along the X or Y axis, ensuring the workpiece reaches its target position when lifted to the required height.

7. The control method for a push-chain driven multi-degree-of-freedom lifting system as described in claim 5, characterized in that: The second control method includes: constructing a "one master, multiple slaves" motion control system using an electronic cam control algorithm via a programmable logic controller (PLC) to achieve coordinated operation of the four lifting platforms; specifically including: A virtual master motion axis Axis0 is set as the motion reference axis to provide a reference position signal; the slave motion axes Axis1, Axis2, Axis3, and Axis4 are the four drive motors M in the third push chain drive mechanism of the four lifting platforms. z1 M z2 M z3 M z4 The output shaft; from the motion axis Axis1 via the electronic cam curve Ecam 10 and Ecam 11 Establish motion coupling with the main motion axis Axis0; from the motion axis Axis2, via the electronic cam curve Ecam 20 and Ecam 21 Establish motion coupling with the main motion axis Axis0; from the motion axis Axis3, via the electronic cam curve Ecam 30 and Ecam 31 Establish motion coupling with the main motion axis Axis0; from the motion axis Axis4 via the electronic cam curve Ecam 40 and Ecam 41 A motion coupling relationship is established with the main motion axis Axis0. Specifically, the motion coupling relationship between the main motion axis and the slave motion axis is as follows: the motion position of the main motion axis Axis0 corresponds one-to-one with the real-time position of each slave motion axis. The slave motion axes Axis1, Axis2, Axis3, and Axis4 all follow the main motion axis according to the set electronic cam relationship. Since the four slave motion axes share the same main motion axis reference signal, the motion cycle of the four slave axes is always consistent, that is, the four carrying platforms reach the target position at the same time. Alternatively, according to the workpiece size requirements, the point displacement of the electronic cam curve is modified, and each lifting platform reaches a different target position at the same time according to its own electronic cam curve parameters.

8. The control method for a push-chain driven multi-degree-of-freedom lifting system as described in claim 7, characterized in that: The second control method further includes: employing a thrust-position coupling judgment mechanism, and installing tension / compression sensors FS between the push chain heads of the four lifting platforms and the bearing platform. z1 FS z2 FS z3 FS z4 Real-time detection of the pressure F at the head of the push chain device zi Set the upper pressure limit F z0 The lifting platform's drive motor is a servo motor. The actual position P of the lifting platform is obtained through bus communication between the servo motor's servo driver and the control mechanism. ri and instruction position P si Calculate the positional deviation ΔPi=P ri P si Set the upper limit of position deviation ΔP0; when ΔPi>ΔP0, the control mechanism starts dynamic balance adjustment, that is, by changing the position of the lifting platform with excessive position deviation, it compensates for the off-center load and offset; when F zi >F z0 If ΔPi > ΔP0 for t0 seconds, the off-center load protection will be triggered immediately, locking the position of the lifting system.

9. The control method for a push-chain driven multi-degree-of-freedom lifting system as described in claim 5, characterized in that: The control method one and control method two work together to enable the four support platforms to be at different heights and positions, so that the four support platforms can adapt to the three-dimensional shape of the workpiece and lift and lower the workpiece.

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