Underground logistics linear motor turning control system and control method thereof

Abstract

The invention relates to an underground logistics linear motor turning control system and a control method thereof, and the system comprises a track module which is formed by connecting a straight track and a turning track; the rotor trolley is arranged on the track module in a running mode; the electromagnet assembly comprises a base and an arc-shaped electromagnet located on the base, and the arc-shaped electromagnet is used for providing electromagnetic attraction force for the mover trolley when the mover trolley runs on the turning track; and the controller is used for supplying power to the straight movement stator, the turning stator and the arc-shaped electromagnet and dynamically adjusting the electromagnetic attraction force of the arc-shaped electromagnet based on the real-time speed of the mover trolley. The structure is simple, a complex mechanical structure is not needed, the derailment risk of the mover trolley is greatly reduced through the combined action of the electromagnetic thrust of the turning stator and the arc-shaped electromagnet, and the fault rate is low.

Description

Technical Field

[0001] This invention relates to the field of linear motor technology, and in particular to a linear motor turning control system and control method for underground logistics. Background Technology

[0002] In the freight transport sector, four major contradictions are particularly prominent: first, the contradiction between surging freight demand and limited road capacity; second, safety conflicts between trucks and other road users; third, the challenge of balancing freight emissions and environmental protection; and fourth, the dilemma of coordinating road resource allocation with freight volume. These contradictions directly lead to problems such as increased road congestion, frequent safety accidents, ecological degradation, and overloaded infrastructure, severely restricting sustainable urban development.

[0003] To address these challenges, a collaborative "above-ground-underground" intelligent logistics system needs to be built. On the one hand, comprehensive measures such as optimizing intelligent transportation systems, promoting green transportation technologies, and scientifically planning freight routes should be implemented to improve the efficiency of surface transportation. On the other hand, development should focus on the development of underground space resources. Since the 20th century, developed countries in Europe and America have taken the lead in exploring the construction of underground logistics systems (ULS), effectively diverting pressure on surface transportation by building underground freight networks. Academician Qian Qihu, a renowned expert in protective engineering in my country, also proactively proposed that developing urban underground logistics networks is a strategic choice for solving road congestion and ecological problems. This innovative transportation model can not only significantly improve logistics efficiency and reduce transportation costs, but will also become an important technological support for sustainable urban development.

[0004] Linear motors, with their high efficiency, high acceleration, high speed, and remote controllability, can fully meet the driving requirements of underground logistics systems. Their working principle is based on electromagnetic action, directly converting electrical energy into linear motion. Structurally, they can be considered as a rotary motor cut radially and flattened. A linear motor mainly consists of a stator (including primary and secondary windings) and a mover (composed of magnetic poles, rotor, armature, etc.).

[0005] However, applying linear motors to underground logistics systems faces a key challenge: insufficient steering capability. Because underground logistics networks require a complex network of routes (such as branching intersections, crossroads, and ring roads), the unidirectional electromagnetic thrust characteristics and rigid stator structure of traditional linear motors are ill-suited to the steering requirements of complex paths, severely limiting their mobility. For example, the German CargoCap project uses a rotating turntable or track translation mechanism at track intersections to switch the direction of travel of the mover through physical displacement; this method suffers from extremely low steering speed, complex mechanical structure, high failure rate, and damage to the efficient continuous operation characteristics of linear motors. The invention patent with publication number CN119976415A employs a technique that leaves a gap between the stators and relies on the inertia of the mover to navigate curved areas; this method suffers from the risk of high-speed derailment of the mover, control inaccuracies, and inability to adapt to curves with small curvatures. Japan's underground logistics experimental line uses a multi-motor cooperative scheduling method for steering control, that is, a central controller coordinates the passage sequence of multiple motors at intersections. This method has technical drawbacks such as low logistics efficiency, high collision risk, and inability to support high-density transportation. Therefore, there is an urgent need for a new type of turning control system that is simple in structure, has a low failure rate, and high operating efficiency, while retaining the efficient straight-line capability of linear motors and overcoming the limitations of steering flexibility to achieve full topology coverage of the underground logistics network. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an underground logistics linear motor turning control system and control method that can achieve flexible steering, has a simple structure, low failure rate, and high operating efficiency.

[0007] In a first aspect, the technical solution adopted by the present invention is a linear motor turning control system for underground logistics, comprising:

[0008] The track module is composed of a straight track and a turning track connected together. The straight track includes a straight track body and a plurality of straight stators arranged linearly at intervals within the straight track body. The turning track includes a turning track body and a turning stator arranged within the turning track body. The radius of curvature of the turning stator is equal to the radius of the turning track body.

[0009] The moving trolley runs on the track module. The moving trolley includes a frame, a permanent magnet array disposed in the frame, and a steering mechanism rotatably connected to the frame. The steering mechanism includes wheels, wheel frames rotatably connected to the wheels, and steering bearings. The wheel frames are rotatably connected to the frame through the steering bearings. The wheel frames are made of ferromagnetic material.

[0010] An electromagnet assembly includes a base and an arc-shaped electromagnet located on the base. The arc-shaped electromagnet includes a working surface that conforms to the inner arc wall of the turning track body. The radius of curvature of the working surface is equal to the radius of the turning track body. The arc-shaped electromagnet is used to provide electromagnetic attraction to the moving trolley when the moving trolley is running on the turning track.

[0011] The controller is electrically connected to the straight stator, the turning stator, and the arc electromagnet. The controller is used to supply power to the straight stator, the turning stator, and the arc electromagnet, and to dynamically adjust the electromagnetic attraction force of the arc electromagnet based on the real-time speed of the moving trolley.

[0012] The beneficial effects of this invention are as follows: Using the aforementioned underground logistics linear motor turning control system, the controller energizes the straight-moving stator, generating an electromagnetic field that interacts with the permanent magnet array to drive the moving trolley straight along the straight track. The controller also energizes the turning stator and the arc-shaped electromagnet. The turning stator generates an electromagnetic field that interacts with the permanent magnet array on the moving trolley, providing thrust to the moving trolley. Simultaneously, combined with the electromagnetic attraction provided by the arc-shaped electromagnet, the moving trolley completes the turning motion, achieving flexible steering. This structure is simple, requiring no complex mechanical structures. The combined effect of the electromagnetic thrust of the turning stator and the arc-shaped electromagnet significantly reduces the risk of derailment of the moving trolley, resulting in a low failure rate. It eliminates the need for multiple moving trolleys to coordinate, improving operational efficiency and achieving full topology coverage of the underground logistics network.

[0013] Preferably, the controller includes an electromagnetic attraction force adjustment unit, which is used to calculate the relationship between the real-time speed V and the electromagnetic attraction force F based on the real-time speed V of the moving trolley on the turning track. n Pareto optimal solution (V * F n * The current I passing through the arc-shaped electromagnet is dynamically adjusted according to the Pareto optimal solution, providing electromagnetic attraction to the moving trolley as it runs on the turning track. This structure dynamically matches the real-time speed of the moving trolley on the turning track with the electromagnetic attraction, ensuring that the moving trolley completes turning operations more safely and efficiently.

[0014] Preferably, the arc-shaped electromagnet is electrically connected to the controller via an H-bridge drive circuit, and the electromagnetic attraction force adjustment unit is used to adjust the current I passing through the arc-shaped electromagnet via the H-bridge drive circuit to satisfy: Where d represents the distance between the electromagnet and the moving core; F aThe vector represents the centripetal force acting on the moving carriage; μ0 represents the vacuum permeability; N represents the number of turns in the internal coil of the electromagnet; and A0 represents the cross-sectional area of ​​the magnetic pole. Using this structure, the controller adjusts the current passing through the arc-shaped electromagnet via an H-bridge drive circuit, thereby providing the moving carriage with an electromagnetic attraction force equal to the centripetal force during turning, enabling the moving carriage to achieve stable, flexible, and efficient turning.

[0015] Preferably, the straight track further includes a linear Hall plate disposed within the straight track body, corresponding one-to-one with each straight stator. The linear Hall plate is located on one side of the corresponding straight stator, and a plurality of first Hall sensors electrically connected to the controller are disposed on the linear Hall plate. The turning track further includes an arc-shaped Hall plate disposed within the turning track body, corresponding to the turning stator. The arc-shaped Hall plate is located on one side of the turning stator, and a plurality of second Hall sensors electrically connected to the controller are disposed on the arc-shaped Hall plate. With this structure, when the moving trolley is located on the straight track or the turning track, the permanent magnet array on the moving trolley senses the Hall sensors. The magnetic field generated by the permanent magnet array causes the Hall sensors to generate an electrical signal, which is fed back to the controller. After receiving the electrical signal from the Hall sensors, the controller energizes the linear stator or the turning stator. The energization of the linear stator or the turning stator generates an electromagnetic field that provides thrust to the moving trolley. This structure is simple, requires no complex mechanical structure, and ensures high-efficiency operation of the moving trolley.

[0016] Preferably, the linear Hall plate includes a first front end protruding from the front end of the corresponding straight stator and a first rear end protruding from the rear end of the corresponding straight stator. A plurality of first Hall sensors are distributed at equal intervals from the first front end along the direction of the first rear end. The arc-shaped Hall plate includes a second front end protruding from the front end of the corresponding arc-shaped stator and a second rear end protruding from the rear end of the corresponding arc-shaped stator. A plurality of second Hall sensors are distributed at equal intervals from the second front end along the direction of the second rear end. With this structure, when the moving trolley is about to enter the next straight stator on the straight track, an electrical signal is generated by the Hall sensor located at the first front end of the Hall plate on the corresponding straight stator and the moving trolley. This electrical signal is fed back to the controller. After receiving the electrical signal from the Hall sensor, the controller powers on the next straight stator, ensuring stable operation of the moving trolley on the straight track. Similarly, the same principle applies to the moving trolley on the turning track.

[0017] Preferably, the plurality of first Hall sensors are embedded in pairs within the linear Hall plate, with each pair of first Hall sensors having a phase difference of 90 electrical degrees, and the distance between two adjacent pairs of first Hall sensors being an integer multiple of the distance corresponding to 180 electrical degrees; the plurality of second Hall sensors are embedded in pairs within the arc-shaped Hall plate, with each pair of second Hall sensors having a phase difference of 90 electrical degrees, and the distance between two adjacent pairs of second Hall sensors being an integer multiple of the distance corresponding to 180 electrical degrees. With this structure, the second Hall sensors, while sensing the permanent magnet array in the moving trolley, also detect the position information of the moving trolley, and obtain the speed of the moving trolley based on the position information. By embedding the second Hall sensors in pairs within the Hall plate, with the phase angle difference between the two second Hall sensors in each pair being 90 degrees, and the distance between each pair of second Hall sensors being an integer multiple of 180 electrical degrees, the position and speed of the moving trolley can be accurately detected.

[0018] Preferably, the wheel frame includes a pair of wheel frames located forward of the moving trolley and a pair of wheel frames located rearward of the moving trolley; the steering mechanism further includes two damping springs, spring fixing rods, and two steering linkages. The two damping springs are respectively fixed to the frame by the spring fixing rods, one end of each damping spring is connected to the pair of wheel frames forward of the moving trolley, and the other end of each damping spring is connected to the pair of wheel frames rearward of the moving trolley; both ends of one steering linkage are connected to the pair of wheel frames forward of the moving trolley, and both ends of the other steering linkage are connected to the pair of wheel frames rearward of the moving trolley; with this structure, the front and rear wheels of the moving trolley can be steered synchronously, the damping springs can prevent the moving trolley from steering too flexibly and assist in automatic return to center; the steering linkages play a linkage role, ensuring synchronous steering of the front and rear wheels.

[0019] Preferably, the turning stator is integrally formed by CNC machining. This structure avoids the processing difficulties caused by traditional lamination processing, and the CNC integral forming simplifies the processing.

[0020] Secondly, the technical solution adopted by this invention is a control method for a linear motor turning control system for underground logistics, the method comprising the following steps:

[0021] (1) Straight-through control phase:

[0022] (1-1) When the moving trolley is about to enter the top of the straight stator at a certain speed, the moving trolley triggers the first Hall sensor at the first rear end of the straight Hall plate corresponding to the straight stator, and the controller executes: a. turning off the power supply to the previous straight stator; b. starting the three-phase current of the straight stator; c. performing closed-loop regulation on the real-time speed of the moving trolley.

[0023] (1-2) When the moving trolley disengages from the linear stator, the moving trolley triggers the first Hall sensor at the first front end of the linear Hall plate corresponding to the linear stator, and the controller cuts off the power supply to the linear stator. The moving trolley then transitions into the range of the next linear stator by inertia.

[0024] (2) Turning control phase:

[0025] (2-1) When the moving trolley leaves the last section of the straight stator on the straight track, the moving trolley triggers the first Hall sensor at the first front end of the straight Hall plate corresponding to the last section of the straight stator. The controller calculates the power supply current of the arc electromagnet according to the real-time speed of the moving trolley and starts the H-bridge drive circuit to power the arc electromagnet.

[0026] (2-2) The moving trolley transitions into the range of the turning stator by inertia. The turning stator triggers the second Hall sensor at the second rear end of the arc-shaped Hall plate. The controller executes: a) shutting off the power supply to the last section of the straight stator; b) starting the current of the turning stator; c) acquiring the real-time speed of the moving trolley, and solving the relationship between the real-time speed V and the electromagnetic attraction F based on the real-time speed V of the moving trolley on the turning track. n Pareto optimal solution (V * F n * The current I passing through the arc electromagnet is dynamically adjusted according to the Pareto optimal solution.

[0027] (2-3) The second Hall sensor at the second front end of the arc-shaped Hall plate is triggered by the turning stator, and the controller cuts off the power supply to the turning stator and the arc-shaped electromagnet.

[0028] Preferably, the three-phase current of the vertical stator is specifically expressed as follows:

[0029] Among them, I m =K p (v ref -v0); K p Indicates: Represents proportional gain, v ref v0 represents the expected velocity of the given moving trolley; v0 represents the initial velocity of the moving trolley.

[0030] Preferably, the specific process of closed-loop adjustment of the real-time speed of the moving trolley includes the following steps:

[0031] S1.1 The controller obtains the real-time speed v of the moving trolley on the straight track through the first Hall sensor. mean ;

[0032] S1.2 The controller calculates the speed error, which is expressed as: e v =v ref -v means ; where v ref This represents the expected speed of a given moving trolley;

[0033] S1.3 The controller performs PI regulation on the speed error and outputs a q-axis current reference value. Specifically, it is expressed as follows: Among them, K p K represents the proportional gain. i This represents the integral gain.

[0034] S1.4, will Compared with the actual value of q-axis current The difference is obtained by comparison. Based on the difference, the PWM output voltage signal in the controller is controlled. The SVPWM in the controller generates a three-phase PWM waveform based on the voltage signal output by the PWM. Based on the three-phase PWM waveform, the inverter outputs a three-phase current to the corresponding direct stator. After receiving the three-phase current, the corresponding direct stator changes the electromagnetic field, thereby adjusting the real-time speed of the mover trolley.

[0035] 10. Preferably, the method involves solving for the real-time velocity V and the electromagnetic attraction force F based on the real-time velocity V of the moving trolley on the turning track. n Pareto optimal solution (V * F n * The specific process of dynamically adjusting the current I passing through the arc electromagnet according to the Pareto optimal solution includes the following steps:

[0036] S2.1 Establishing the electromagnetic attraction force requirement model for the arc-shaped electromagnet: Based on the mass of the moving trolley, the turning radius, and the friction coefficient, determine the system constant k, and obtain the theoretical electromagnet attraction force F. req =k·V 2 ;

[0037] S2.2 Construct a multi-objective optimization function, which includes two objectives: the first objective is to maximize the speed performance min(-V); the second objective is to minimize the actual electromagnet attraction force F. n Compared with the theoretical value F reqdeviation min|F n -kV 2 |;

[0038] S2.3, Set constraints: α·k·V 2 ≤F n ≤F max And V∈[V min V max ]; where α represents the safety factor, α∈(0.8,0.95); V min V represents the minimum constrained speed of the moving trolley. max This indicates the maximum constrained speed of the moving trolley;

[0039] 2. S2.4. Use the NSGA-II multi-objective evolutionary algorithm to solve the multi-objective optimization function described in step S2.2, and generate the Pareto optimal solution (V). * F n * According to the Pareto optimal solution, the current I passing through the arc electromagnet is dynamically adjusted through the H-bridge drive circuit so that the current I passing through the arc electromagnet satisfies: Where d represents the distance between the electromagnet and the moving core; F a The value represents the centripetal force acting on the moving carriage; μ0 represents the vacuum permeability; N represents the number of turns of the coil inside the electromagnet; and A0 represents the cross-sectional area of ​​the magnetic pole. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of a linear motor turning control system for underground logistics according to the present invention;

[0041] Figure 2 This is a schematic diagram of the moving trolley in a linear motor turning control system for underground logistics according to the present invention;

[0042] Figure 3 This is an exploded view of the moving trolley in this invention;

[0043] Figure 4 This is a schematic diagram of the steering mechanism of the moving trolley in this invention;

[0044] Figure 5 This is a schematic diagram of the linear Hall plate in this invention;

[0045] Figure 6 This is a waveform diagram illustrating the ideal signal detected by the Hall sensor and the position information analyzed in this invention;

[0046] Figure 7 This is a schematic diagram of the structure of the turning stator in this invention;

[0047] As shown in the figure: 1. Moving trolley; 2. Straight-moving stator; 3. First Hall sensor; 4. Turning track; 5. Electromagnet base; 6. Arc-shaped electromagnet; 7. Turning stator; 8. Second Hall sensor; 9. Straight-moving track; 10. Linear Hall plate; 11. Chassis; 12. Steering mechanism; 13. Arc-shaped Hall plate; 111. Moving core; 112. Permanent magnet mounting base; 113. Permanent magnet array; 121. Wheel frame; 122. Steering bearing; 123. Damping spring; 124. Spring fixing rod; 125. Steering linkage. Detailed Implementation

[0048] The invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can implement it based on the description. The scope of protection of the invention is not limited to these specific embodiments.

[0049] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0050] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0051] In the description of the embodiments of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0052] This invention relates to a linear motor turning control system for underground logistics, such as... Figure 1 As shown, it includes: a track module, a moving trolley, an electromagnet assembly, and a controller.

[0053] Figure 1 In the middle, the track module consists of straight tracks and turning tracks connected together, and the straight tracks and turning tracks are rigidly connected by flanges.

[0054] Figure 1The linear guideway includes a linear guideway body and several linear stators arranged linearly along the axis of the linear guideway body. The linear guideway body is made of high-strength aluminum alloy profile (yield strength ≥ 300MPa), with a U-shaped groove structure, a groove depth of 50mm, and a width of 120mm. The spacing between adjacent linear stators is set to 15cm, and the length of each linear stator segment is 1.2m. The stator core of the linear stator is formed by stacking 0.35mm thick DW310-35 silicon steel sheets, with a total of 36 slots. Each slot is embedded with a coil wound with φ0.8mm enameled wire, with 120 turns and a pole pitch τ. P =18mm, the three-phase winding adopts Y-type connection.

[0055] like Figure 1 As shown, the straight track also includes linear Hall plates disposed within the straight track body, corresponding one-to-one with each straight stator. The linear Hall plates are located on one side of the corresponding straight stator, such as... Figure 5 As shown, the linear Hall plate is provided with a plurality of first Hall sensors electrically connected to the controller. The linear Hall plate includes a first front end protruding from the front end of the corresponding straight stator and a first rear end protruding from the rear end of the corresponding straight stator. The length of the linear Hall plate is 500mm (25mm beyond the front and rear ends of the straight stator) and the width is 30mm.

[0056] like Figure 2 As shown, a plurality of first Hall sensors on the linear Hall plate are distributed at equal intervals from the first front end along the direction of the first rear end; the plurality of first Hall sensors on the linear Hall plate are embedded in the linear Hall plate in pairs. Figure 5 As shown, a total of four pairs of first Hall sensors are embedded in the linear Hall plate. The first pair of first Hall sensors is located inside the first front end, the second and third pairs are located between the first front end and the first rear end, and the fourth pair is located inside the first rear end. The phase difference between each pair of first Hall sensors on the linear Hall plate is 90 electrical degrees, and the distance between two adjacent pairs of first Hall sensors is an integer multiple of the distance corresponding to 180 electrical degrees. This allows for precise detection of the position and speed of the moving trolley. The first Hall sensors sense the permanent magnet array in the moving trolley while simultaneously detecting the position and speed information of the moving trolley. The first Hall sensors on the linear Hall plate are TIDRV5053OA linear Hall sensors with a sensitivity of 1.5mV / Gauss and a bandwidth of 10kHz.

[0057] The straight stator is electrically connected to the controller, and the four pairs of first Hall sensors on the linear Hall plate are also electrically connected to the controller. When the moving trolley enters the straight track at a certain speed and is about to enter above the straight stator, the first Hall sensor at the rear end of the linear Hall plate corresponding to the straight stator first senses and generates an electrical signal. This signal is fed back to the controller, which calculates the current position and speed of the moving trolley. As the moving trolley runs above the straight stator, it sequentially senses the first Hall sensors on the linear Hall plate, and the controller calculates the current position and speed of the moving trolley in real time. The controller's main control chip uses a TI TMS320F28379D dual-core DSP (200MHz).

[0058] like Figure 1 As shown, the turning track includes a turning track body and a turning stator disposed within the turning track body. The radius of curvature of the turning stator is equal to the radius of the turning track body, and the radius of curvature of the turning stator is 1.5m. The arc-shaped iron core of the turning stator is integrally machined by CNC, avoiding the difficulties of lamination processing and reducing eddy current losses. The material of the arc-shaped iron core is SMC soft magnetic composite material, with a loss of <5W / kg@1T / 1kHz. The arc length of the turning stator corresponds to a central angle of 60°, and 24 slots are evenly distributed along the circumference. The coil parameters are the same as those of the straight stator. The distance between the last section of the straight stator and the turning stator on the straight track is set to 15cm.

[0059] like Figure 1 As shown, the turning track also includes an arc-shaped Hall plate disposed within the turning track body corresponding to the turning stator. The arc-shaped Hall plate is located on one side of the turning stator, and several second Hall sensors electrically connected to the controller are disposed on the arc-shaped Hall plate. When the moving trolley is located on the turning track, the permanent magnet array on the moving trolley senses the second Hall sensors. The magnetic field generated by the permanent magnet array causes the second Hall sensors to generate an electrical signal, which is fed back to the controller. After receiving the electrical signal from the second Hall sensors, the controller energizes the turning stator. The energized turning stator generates an electromagnetic field that provides thrust to the moving trolley. This structure is simple, requires no complex mechanical structure, and ensures high-efficiency operation of the moving trolley.

[0060] The arc-shaped Hall plate includes a second front end protruding from the front end of the corresponding arc-shaped stator and a second rear end protruding from the rear end of the corresponding arc-shaped stator. A plurality of second Hall sensors are distributed at equal intervals from the second front end along the direction of the second rear end. The plurality of second Hall sensors are embedded in pairs within the arc-shaped Hall plate, with a total of four pairs of second Hall sensors embedded in the arc-shaped Hall plate. The first pair of second Hall sensors is located within the second front end, the second and third pairs of second Hall sensors are located between the second front and second rear ends, and the fourth pair of second Hall sensors is located within the second rear end. When the moving trolley is about to enter the turning track, the second Hall sensor located at the second rear end of the Hall plate corresponding to the turning stator senses the movement of the moving trolley and generates an electrical signal. This electrical signal is fed back to the controller. Upon receiving the electrical signal from the second Hall sensor, the controller powers on the turning stator, ensuring the stable operation of the moving trolley on the turning track.

[0061] The phase difference between each pair of second Hall sensors on the arc-shaped Hall plate is 90 electrical degrees, and the distance between two adjacent pairs of second Hall sensors is an integer multiple of the distance corresponding to 180 electrical degrees. While the second Hall sensors are sensing the permanent magnet array in the moving vehicle, they are also detecting the position and speed information of the moving vehicle. The second Hall sensors are embedded in the arc-shaped Hall plate in pairs, and the phase angle between the two second Hall sensors in each pair is 90 degrees, and the distance between each pair of second Hall sensors is an integer multiple of 180 electrical degrees. In this way, the position and speed of the moving vehicle can be accurately detected.

[0062] The turning stator is electrically connected to the controller, and the four pairs of second Hall sensors on the arc-shaped Hall plate are also electrically connected to the controller. When the moving trolley reaches the end of the last straight stator on the straight track, the Hall sensor at the first front end of the straight Hall plate corresponding to the last straight stator generates an electrical signal. This signal is fed back to the controller, which then de-energizes the last straight stator. The moving trolley then transitions into the turning stator's range due to inertia. The Hall sensor at the second rear end of the arc-shaped Hall plate corresponding to the turning stator generates an electrical signal, which is also fed back to the controller. The controller calculates the moving trolley's current position and speed, and simultaneously energizes the turning stator. The controller acquires the moving trolley's speed in real time.

[0063] like Figure 1 As shown, the electromagnet assembly includes a base and an arc-shaped electromagnet located on the base. The arc-shaped electromagnet includes a working surface that conforms to the inner arc wall of the turning track body. The radius of curvature of the working surface is equal to the radius of the turning track body, and the radius of curvature R of the working surface is...l =1.5m, the working surface width is 80mm, and the magnetic pole area A0 = 0.012m² 2 Since the wheel frame of the moving trolley is made of ferromagnetic material, it provides electromagnetic attraction when the trolley is running on the turning track. The electromagnetic attraction is specifically represented as follows: Where μ0 is the vacuum permeability, N represents the effective number of turns per pole per phase of the stator winding of the turning stator, I represents the current through the arc electromagnet, A0 represents the magnetic pole area of ​​the stator winding of the turning stator, and d represents the air gap distance.

[0064] like Figure 1 As shown, the arc-shaped electromagnet is electrically connected to the controller via an H-bridge drive circuit. The controller is used to adjust the current I passing through the arc-shaped electromagnet according to the real-time speed of the moving trolley via the H-bridge drive circuit, so that the current I passing through the arc-shaped electromagnet satisfies: Where d represents the distance between the electromagnet and the moving core; F a The vector represents the centripetal force acting on the moving carriage; μ0 represents the vacuum permeability; N represents the number of turns in the internal coil of the electromagnet; and A0 represents the cross-sectional area of ​​the magnetic pole. Using this structure, the H-bridge drive circuit supports PWM current regulation. The controller adjusts the current passing through the arc-shaped electromagnet through the H-bridge drive circuit, thereby providing the moving carriage with an electromagnetic attraction force equal to the centripetal force when the moving carriage turns, enabling the moving carriage to achieve stable, flexible, and efficient turning.

[0065] like Figure 3 As shown, the movable trolley runs on the track module. The movable trolley includes a frame, a permanent magnet array disposed within the frame, and a steering mechanism rotatably connected to the frame. The frame is made of carbon fiber composite material with a density of 1.6 g / cm³. 3 (Bending stiffness 120 GPa). The permanent magnet array installed in the frame includes 5 pairs of permanent magnets, which are neodymium iron boron permanent magnets arranged in a Halbach array, with a magnetic flux density of 1000 NdFeB. The pole gap is 60mm, and 5 pairs of permanent magnets are attached to the bottom of the frame.

[0066] like Figure 4 As shown, the steering mechanism includes wheels, wheel carriers rotatably connected to the wheels, and steering bearings. The wheel carriers are rotatably connected to the frame via the steering bearings, and are made of ferromagnetic material. The steering bearings are SKF 61900-2RS1 deep groove ball bearings with an inner diameter of 10mm, an outer diameter of 22mm, and an axial load of 1.2kN. The wheel carriers include a pair of wheel carriers located at the front of the moving carriage and a pair of wheel carriers located at the rear of the moving carriage, with the four wheel carriers rotatably connected to the four wheels respectively.

[0067] like Figure 5 As shown, the steering mechanism further includes two damping springs, spring fixing rods, and two steering linkages. The two damping springs are fixed to the frame via the spring fixing rods. One end of each damping spring is connected to a pair of forward-facing wheel frames of the moving trolley, and the other end is connected to a pair of rearward-facing wheel frames of the moving trolley. One steering linkage has both ends connected to the forward-facing wheel frames of the moving trolley, and the other steering linkage has both ends connected to the rearward-facing wheel frames of the moving trolley. This structure enables synchronous steering of the front and rear wheels of the moving trolley. The damping springs prevent excessive steering and assist in automatic return to center. The steering linkages provide linkage, ensuring synchronous steering of the front and rear wheels. The damping spring stiffness coefficient k = 50 N / mm, pre-compression force 100 N, and installation tilt angle 45°. The steering linkage length L = 400 mm (front and rear wheel track), and the synchronization error <0.1°.

[0068] A Hall sensor is a position sensor that utilizes the Hall effect to linearly detect the output voltage signal that varies with the magnitude of magnetic induction within a certain magnetic field range. For a sinusoidally driven moving-magnet permanent magnet synchronous motor, changes in the mover's position cause changes in the air gap magnetic field inside the motor, and the magnetic field change at the same position exhibits a sinusoidal pattern. Therefore, Hall sensors can be used to obtain the mover's position and velocity information. Since the same voltage value of the sinusoidal voltage signal generated by a single linear Hall sensor corresponds to two angle values, it cannot directly express the unique mover position and direction of motion. Therefore, an even number of linear Hall sensors are often used in combination to solve for the position. To simplify the explanation of the basic principle, it is assumed that two linear Hall sensors with a 90° electrical angle difference are installed on the motor. The angular position information in the figure represents the position information. Ignoring the DC bias effect of the sensors themselves, the linear Hall sensor will output as shown in the figure. s and H c The two signals shown are as follows: Figure 6 As shown, these two mutually orthogonal voltage signals can be used as the sine and cosine function values ​​of the electrical angle at the position of the mover, that is: In the formula, H s and H c The output voltages of the two Hall sensors represent the sine and cosine values ​​of the current position. θ is the ideal electrical angle position of the motor mover with a period of 2π. The output voltage of the linear Hall sensor at the maximum air gap magnetic induction intensity is A, and T is used to represent the period of one electrical angle position.

[0069] In the motion control system of the moving part, the real-time velocity V of the moving part trolley on the turning track is related to the electromagnet attraction force F. nThese are two key parameters. To achieve safe and efficient turning operations, the real-time speed V and the electromagnet force must be coordinated and matched. Generally, the higher the speed of the moving part, the greater the centrifugal force required for turning, thus placing higher torque demands on the steering system. If the electromagnet force is insufficient, it will be unable to overcome inertia, resulting in the inability to complete the turn; if the electromagnet force exceeds the system's tolerance limit, it may cause the moving part to jam and control failure. Therefore, the controller in the underground logistics linear motor turning control system of this invention also includes an electromagnetic force adjustment unit, which is used to solve the relationship between the real-time speed V and the electromagnetic force F based on the real-time speed V of the moving part trolley on the turning track. n Pareto optimal solution (V * F n * The current I passing through the arc electromagnet is dynamically adjusted according to the Pareto optimal solution, so that the moving trolley provides electromagnetic attraction when it runs on the turning track.

[0070] This invention also relates to a control method for a linear motor turning control system for underground logistics, the method comprising the following steps:

[0071] (1) Straight-through control phase:

[0072] (1-1) When the moving trolley is about to enter the top of the straight stator at a certain speed, the moving trolley triggers the Hall sensor at the first rear end of the straight Hall plate corresponding to the straight stator, and the controller executes: a. turning off the power supply to the previous straight stator; b. starting the three-phase current of the straight stator; c. performing closed-loop regulation on the real-time speed of the moving trolley.

[0073] (1-2) When the moving trolley disengages from the linear stator, the moving trolley triggers the first Hall sensor at the first front end of the linear Hall plate corresponding to the linear stator, and the controller cuts off the power supply to the linear stator. The moving trolley then transitions into the range of the next linear stator by inertia.

[0074] (2) Turning control phase:

[0075] (2-1) When the moving trolley leaves the last section of the straight stator on the straight track, the moving trolley triggers the first Hall sensor at the first front end of the straight Hall plate corresponding to the last section of the straight stator. The controller calculates the power supply current of the arc electromagnet according to the real-time speed of the moving trolley and starts the H-bridge drive circuit to power the arc electromagnet.

[0076] (2-2) The moving trolley enters the range of the turning stator by inertia. The turning stator triggers the second Hall sensor at the second rear end of the arc-shaped Hall plate. The controller executes: a. turning off the power supply to the last section of the straight stator; b. starting the three-phase current of the turning stator; c. performing closed-loop adjustment of the real-time speed of the moving trolley, calculating the electromagnetic attraction force required by the moving trolley based on the test speed, and adjusting the current through the arc-shaped electromagnet based on the calculated electromagnetic attraction force.

[0077] (2-3) The second Hall sensor at the second front end of the arc-shaped Hall plate is triggered by the turning stator, and the controller cuts off the power supply to the turning stator and the arc-shaped electromagnet.

[0078] In this invention, the specific process of closed-loop adjustment of the real-time speed of the moving trolley includes the following steps:

[0079] S1.1 The controller obtains the real-time speed v of the moving trolley on the straight track through the first Hall sensor. means ;

[0080] S1.2 The controller calculates the speed error, which is expressed as: e v =v ref -v means ; where v ref This represents the expected speed of a given moving trolley;

[0081] S1.3 The controller performs PI regulation on the speed error and outputs a q-axis current reference value. Specifically, it is expressed as follows: Among them, K p K represents the proportional gain. i This represents the integral gain.

[0082] S1.4, will Compared with the actual value of q-axis current The difference is obtained by comparison. Based on the difference, the PWM output voltage signal in the controller is controlled. The SVPWM in the controller generates a three-phase PWM waveform based on the voltage signal output by the PWM. Based on the three-phase PWM waveform, the inverter outputs a three-phase current to the corresponding direct stator. After receiving the three-phase current, the corresponding direct stator changes the electromagnetic field, thereby adjusting the real-time speed of the mover trolley.

[0083] In the above steps, real-time feedback and reference values ​​are used. By comparing the speeds, the real-time speed of the moving carriage is continuously adjusted and the output is modified. Through proportional-integral control, the q-axis current is dynamically adjusted to achieve: fast response (proportional term) + precise zero steady-state error (integral term) = stable and efficient speed tracking.

[0084] In this invention, the motion of the moving trolley during the turning phase is circular motion, which satisfies the circular motion equation (1):

[0085]

[0086] Where m is the mass of the mover; r is the turning radius; V represents the speed of the mover trolley on the turning track; F n F represents the electromagnetic attraction force of an arc-shaped electromagnet; a Centripetal force.

[0087] During the turning phase, the centripetal force is provided by electromagnetic attraction, when F n =F a When the requirements are met, it can make a turn; when F n >F a When the rotor deviates from the track and cannot turn, when F... n <F a At that moment, the mover is centrifugally directed outwards and cannot turn. Therefore, the mover velocity v and the electromagnetic attraction force F... n The decision will determine whether the turnaround can be completed.

[0088] Because during the operation of the moving trolley, there is an electromagnetic thrust F in the horizontal direction of motion (q-axis or quadrature axis). q At the same time, there is an attractive force F generated in the vertical and horizontal directions of motion. d Formula (4) is derived from Maxwell's stress tensor equation, which includes the superposition of the magnetic field generated by the stator winding current and the magnetic field of the permanent magnet.

[0089]

[0090] ψ f N = B·A r · (3)

[0091] In formulas (2) and (3), B r The remanent magnetic flux density (T) of the permanent magnet is typically 0.8-1.3T (for neodymium iron boron materials); A represents the effective magnetic flux channel area passing through the stator winding (m²). 2 The shape of the stator slot and the air gap are determined by the ψ. f The value represents the equivalent flux linkage of the permanent magnet in the stator winding (unit: Wb); N represents the effective number of turns per pole per phase, i q This represents the q-axis current.

[0092]

[0093] In formula (4), B g Let T represent the air gap magnetic flux density; μ0 represent the vacuum permeability; and A represent the area of ​​the permanent magnet facing the stator. In formula (5), B... rμ represents the remanent magnetic flux density (T) of a permanent magnet. r The relative permeability of the permanent magnet (typically 1.05–1.10 for NdFeB); g represents the air gap length (m); δ represents the relative permeability of the permanent magnet. m Permanent magnet thickness (m).

[0094] The acceleration formula is obtained by analyzing the forces acting on the moving trolley. Formula (6) can be used to calculate the acceleration. In the formula, the friction force f and the pressure direction are determined by the mass and attractive force F of the trolley itself. d The specific calculation can be performed according to formula (7).

[0095] F q -f=ma (6)

[0096] f = μF N =μ(mg+F d (7)

[0097] In formulas (6) and (7), f represents the frictional force (N) acting on the mover; m represents the weight of the mover trolley; μ represents the coefficient of friction; F N It indicates support.

[0098] According to the kinematic velocity equation, the relationship between the final velocity and the initial velocity, acceleration and displacement can be obtained as shown in formula (8).

[0099]

[0100] Among them, V t V represents the final velocity; V0 represents the initial velocity; a represents the acceleration; and x represents the displacement.

[0101] Substituting the above formula into formula (1) yields F. a Size and i q Positive correlation, detailed formula is shown in (9).

[0102]

[0103] The electromagnetic attraction F of the arc-shaped electromagnet n The calculation of electromagnetic attraction is a complex problem involving multiple parameters, and the core formula is usually based on Maxwell's law of attraction. Electromagnetic attraction F n The electromagnetic attraction force mainly depends on the magnetic induction intensity (B), the magnetic pole area (A), and the air gap distance (d), while the current (I) of the arc electromagnet indirectly determines the electromagnetic attraction force by affecting the magnetic field strength. According to Maxwell's law, the electromagnetic attraction force of the arc electromagnet can be obtained as formula (10).

[0104]

[0105] Wherein: F nB represents the electromagnetic attraction force of the curved electromagnet (Newtons, N); B represents the magnetic flux density at the air gap (Tesla, T); A0 represents the cross-sectional area of ​​the magnetic poles (square meters, m²). 2 μ0 represents the vacuum permeability.

[0106] The function of current (I): Current flowing through a coil generates a magnetic field, and the magnetic induction intensity B is proportional to the ampere-turns (NI) (N is the number of turns in the coil):

[0107] Increasing the current I will significantly increase B, thereby increasing the electromagnetic attraction F. n ∝I 2 (because F) n ∝B 2 ∝I 2 ).

[0108] The effect of distance (d): Increasing the air gap distance d will drastically reduce the suction force. Actual electromagnetic attraction attenuation ratio d -2 Faster (due to magnetic leakage effect in the magnetic circuit), approximately satisfying:

[0109] Therefore, substituting the above relationship into formula (10) yields a practical simplified formula (11) containing current (I) and distance (d):

[0110]

[0111] Analyzing formulas (9) and (11) according to the correspondence principle of formula (1), it is only necessary to control the quadrature axis current i of the turning stator. q By controlling the current (I) of the arc electromagnet and following the relationship in formula (1), the turning motion of the mover can be achieved.

[0112] Closed-loop regulation of the real-time speed of the moving trolley refers to detecting the actual running speed of the motor moving part in real time and comparing it with the desired speed (set value) to form an error signal. Then, the current or frequency is adjusted through a PI speed regulator to precisely control the motor running speed.

[0113] In the motion control system of the moving part, the real-time velocity V and the electromagnet attraction force F are related. n These are two key parameters. For safe and efficient turning, speed and electromagnet force must be coordinated and matched. Generally, the higher the mover speed, the greater the centrifugal force required for turning, thus placing higher torque demands on the steering system. If the electromagnet force is insufficient, it will be unable to overcome inertia, resulting in the inability to complete the turn; if the electromagnet force exceeds the system's tolerance limit, it may cause the mover to jam and control failure.

[0114] As the velocity V increases, the required electromagnet attraction force F req ~V 2 Rapid growth; insufficient electromagnet attraction (less than αF) req This will cause the mover to fail to complete the steering; the electromagnet's attraction force exceeds the system's upper limit F. max This can cause the actuator to malfunction or the system to jam; therefore, matching the electromagnet attraction force as closely as possible while maintaining speed is a key challenge in the design of the motion control system for the mover.

[0115] Therefore, this invention establishes a multi-objective optimization model based on physical laws to simultaneously optimize the real-time velocity V (unit: m / s) and the electromagnet attraction force F. n (Unit: N) To find the optimal trade-off between speed performance and safe steering, the method includes the following steps:

[0116] Establish an electromagnetic attraction force requirement model for the arc-shaped electromagnet: Determine the system constant k based on the mass of the moving trolley, the turning radius, and the coefficient of friction, and obtain the theoretical electromagnet attraction force F. req =k·V 2 The formula shows that the greater the speed, the more difficult it is for the mover to change its direction of travel, and the greater the electromagnet force required.

[0117] A multi-objective optimization function is constructed, comprising two objectives. The first objective is to maximize the speed performance min(-V), which improves driving efficiency and aims to maximize the mover speed V, thus minimizing the negative speed. The second objective is to minimize the actual electromagnet attraction force F. n Compared with the theoretical value F req deviation min|F n -kV 2 To achieve the ideal steering, it is desirable for the actual electromagnet attraction force F to be close to the theoretically required force F. req The smaller the deviation, the better;

[0118] To meet practical physical constraints, the model introduces the following two nonlinear constraints:

[0119] a. Minimum electromagnet force limit (to prevent turning failure): When the actual electromagnet force is too small (below a certain required proportion), the mover will be unable to complete the turn: F n ≥α·k·V 2 ;

[0120] Where α∈(0,1) is the empirical safety factor, usually set to 0.8–0.95, to reflect the ratio of the actual required minimum electromagnet attraction force to the theoretical value.

[0121] b. Maximum Electromagnetic Force Limitation (Preventing Torque Overflow): The steering system has a torque limit that cannot be exceeded: Fn ≤F max ;

[0122] For reasons of physical and engineering controllability, the following value ranges are set for the two optimization variables:

[0123] V∈[V min V max ];F∈[0,F max ];

[0124] Among them, V min V represents the minimum constrained speed of the moving trolley. max This indicates the maximum constrained speed of the moving trolley;

[0125] In summary, the mathematical expression for the multi-objective optimization model is:

[0126]

[0127] subject to F≥α·k·V 2

[0128] F≤F max

[0129] V∈[V min V max ]

[0130] F∈[0,F max ]

[0131] The Pareto optimal solution set can be obtained by solving the model using the classic multi-objective evolutionary algorithm NSGA-II.

[0132] After solving the model, multiple velocity-electromagnetic attraction combinations will be obtained, each of which is a non-dominated solution under the two objectives of "maximum velocity" and "optimal steering matching". These solutions constitute the "Pareto front", and the Pareto optimal solution (V0) is selected. * F n * This provides a wealth of options for motor control strategies.

[0133] To ensure stable operation of the moving trolley during the turning phase, the design is as follows: Figure 7 The diagram shows a turning stator. Because the turning stator is arc-shaped, with the radius of the arc being the same as the radius of the track at the turning point, it is very difficult to convert it to laminated machining. Therefore, it is manufactured using CNC integrated machining. Due to the integrated machining process, eddy current losses and other losses will exist. Therefore, the core loss, eddy current loss, and copper wire loss were calculated separately.

[0134] The simulation sets the air gap to 8mm. Because turning is similar to the circular motion of a disc motor, the simulation sets the band motion to circular motion, the mover speed to 2rad / s, and the three-phase current to 0-5A. The three-phase currents are set as follows: a·sin(100π×t) and The coil winding uses 0.67mm wire with 200 turns. The coil size gradually increases from a minimum of 20mm to 50mm, and the three-phase connection is Y-type. The simulation data obtained under no-load operation are shown below.

[0135] Table 1 Summary of Loss Calculation Results

[0136]

[0137]

[0138] The losses summarized from the graph are shown in Table 1. Copper losses still account for a larger proportion with increasing current, and in practice, the losses manifest as heat. Core losses are relatively stable with changes in current.

Claims

1. A linear motor turning control system for underground logistics, characterized in that: include: The track module is composed of a straight track and a turning track connected together. The straight track includes a straight track body and a plurality of straight stators arranged linearly at intervals within the straight track body. The turning track includes a turning track body and a turning stator arranged within the turning track body. The radius of curvature of the turning stator is equal to the radius of the turning track body. The moving trolley runs on the track module. The moving trolley includes a frame, a permanent magnet array disposed in the frame, and a steering mechanism rotatably connected to the frame. The steering mechanism includes wheels, wheel frames rotatably connected to the wheels, and steering bearings. The wheel frames are rotatably connected to the frame through the steering bearings. The wheel frames are made of ferromagnetic material. An electromagnet assembly includes a base and an arc-shaped electromagnet located on the base. The arc-shaped electromagnet includes a working surface that conforms to the inner arc wall of the turning track body. The radius of curvature of the working surface is equal to the radius of the turning track body. The arc-shaped electromagnet is used to provide electromagnetic attraction to the moving trolley when the moving trolley is running on the turning track. The controller is electrically connected to the straight stator, the turning stator, and the arc electromagnet. The controller is used to supply power to the straight stator, the turning stator, and the arc electromagnet, and to dynamically adjust the electromagnetic attraction force of the arc electromagnet based on the real-time speed of the moving trolley.

2. The underground logistics linear motor turning control system according to claim 1, characterized in that: The controller includes an electromagnetic attraction force adjustment unit, which is used to calculate the relationship between the real-time speed V and the electromagnetic attraction force F based on the real-time speed V of the moving trolley on the turning track. n Pareto optimal solution (V * F n * The current I passing through the arc electromagnet is dynamically adjusted according to the Pareto optimal solution, so that the moving trolley provides electromagnetic attraction when it runs on the turning track.

3. The underground logistics linear motor turning control system according to claim 2, characterized in that: The arc-shaped electromagnet is electrically connected to the controller via an H-bridge drive circuit. The electromagnetic attraction force adjustment unit is used to adjust the current I passing through the arc-shaped electromagnet via the H-bridge drive circuit to satisfy the following: Where d represents the distance between the electromagnet and the moving core in the moving trolley; F a The value represents the centripetal force acting on the moving carriage; μ0 represents the vacuum permeability; N represents the number of turns of the coil inside the electromagnet in the moving carriage; and A0 represents the cross-sectional area of ​​the magnetic pole.

4. A linear motor turning control system for underground logistics according to claim 1 or 3, characterized in that: The straight track further includes a linear Hall plate disposed within the straight track body, corresponding one-to-one with each straight stator. The linear Hall plate is located on one side of the corresponding straight stator, and a plurality of first Hall sensors electrically connected to the controller are disposed on the linear Hall plate. The turning track further includes an arc-shaped Hall plate disposed within the turning track body, corresponding to the turning stator. The arc-shaped Hall plate is located on one side of the turning stator, and a plurality of second Hall sensors electrically connected to the controller are disposed on the arc-shaped Hall plate.

5. A linear motor turning control system for underground logistics according to claim 4, characterized in that: The linear Hall plate includes a first front end protruding from the front end of the corresponding straight stator and a first rear end protruding from the rear end of the corresponding straight stator. A plurality of first Hall sensors are distributed at equal intervals from the first front end along the direction of the first rear end. The arc-shaped Hall plate includes a second front end protruding from the front end of the corresponding arc-shaped stator and a second rear end protruding from the rear end of the corresponding arc-shaped stator. A plurality of second Hall sensors are distributed at equal intervals from the second front end along the direction of the second rear end. The plurality of first Hall sensors are embedded in the linear Hall plate in pairs, with a phase difference of 90 electrical degrees between each pair of first Hall sensors, and the distance between two adjacent pairs of first Hall sensors is an integer multiple of the distance corresponding to 180 electrical degrees. The plurality of second Hall sensors are embedded in the arc-shaped Hall plate in pairs, with a phase difference of 90 electrical degrees between each pair of second Hall sensors, and the distance between two adjacent pairs of second Hall sensors is an integer multiple of the distance corresponding to 180 electrical degrees.

6. The underground logistics linear motor turning control system according to claim 1, characterized in that: The wheel frame includes a pair of wheel frames located in the forward direction of the moving trolley and a pair of wheel frames located in the rearward direction of the moving trolley; the steering mechanism also includes two damping springs, spring fixing rods, and two steering linkages. The two damping springs are respectively fixed to the frame by the spring fixing rods. One end of each damping spring is connected to the pair of wheel frames in the forward direction of the moving trolley, and the other end of each damping spring is connected to the pair of wheel frames in the rearward direction of the moving trolley; both ends of one steering linkage are connected to the pair of wheel frames in the forward direction of the moving trolley, and both ends of the other steering linkage are connected to the pair of wheel frames in the rearward direction of the moving trolley.

7. The underground logistics linear motor turning control system according to claim 1, characterized in that: The aforementioned turning stator is integrally machined using CNC machining.

8. A control method for an underground logistics linear motor turning control system, implemented in any one of claims 1 to 7, characterized in that: The method includes the following steps: (1) Straight-through control phase: (1-1) When the moving trolley is about to enter the top of the straight stator at a certain speed, the moving trolley triggers the first Hall sensor at the first rear end of the straight Hall plate corresponding to the straight stator, and the controller executes: a. turning off the power supply to the previous straight stator; b. starting the three-phase current of the straight stator; c. performing closed-loop regulation on the real-time speed of the moving trolley. (1-2) When the moving trolley disengages from the linear stator, the moving trolley triggers the first Hall sensor at the first front end of the linear Hall plate corresponding to the linear stator, and the controller cuts off the power supply to the linear stator. The moving trolley then transitions into the range of the next linear stator by inertia. (2) Turning control phase: (2-1) When the moving trolley leaves the last section of the straight stator on the straight track, the moving trolley triggers the first Hall sensor at the first front end of the straight Hall plate corresponding to the last section of the straight stator. The controller calculates the power supply current of the arc electromagnet according to the real-time speed of the moving trolley and starts the H-bridge drive circuit to power the arc electromagnet. (2-2) The moving trolley transitions into the range of the turning stator by inertia. The turning stator triggers the second Hall sensor at the second rear end of the arc-shaped Hall plate. The controller executes: a) shutting off the power supply to the last section of the straight stator; b) starting the current of the turning stator; c) acquiring the real-time speed V of the moving trolley on the turning track, and solving the relationship between the real-time speed V and the electromagnetic attraction force F. n Pareto optimal solution (V * F n * The current I passing through the arc electromagnet is dynamically adjusted according to the Pareto optimal solution. (2-3) The second Hall sensor at the second front end of the arc-shaped Hall plate is triggered by the turning stator, and the controller cuts off the power supply to the turning stator and the arc-shaped electromagnet.

9. The control method for a linear motor turning control system for underground logistics according to claim 8, characterized in that: The specific process of closed-loop adjustment of the real-time speed of the moving trolley includes the following steps: S1.1 The controller obtains the real-time speed v of the moving trolley on the straight track through the first Hall sensor. means ; S1.2 The controller calculates the speed error, which is expressed as: e v =v ref -v means ; Among them, v ref This represents the expected speed of a given moving trolley; S1.3 The controller performs PI regulation on the speed error and outputs a q-axis current reference value. Specifically, it is expressed as follows: Among them, K p K represents the proportional gain. i This represents the integral gain. S1.4, will Compared with the actual value of q-axis current The difference is obtained by comparison. Based on the difference, the PWM output voltage signal in the controller is controlled. The SVPWM in the controller generates a three-phase PWM waveform based on the voltage signal output by the PWM. Based on the three-phase PWM waveform, the inverter outputs a three-phase current to the corresponding direct stator. After receiving the three-phase current, the corresponding direct stator changes the electromagnetic field, thereby adjusting the real-time speed of the mover trolley.

10. The control method for a linear motor turning control system for underground logistics according to claim 8, characterized in that: The above describes the solution of real-time velocity V and electromagnetic attraction F based on real-time velocity V. n Pareto optimal solution (V * F n * The specific process of dynamically adjusting the current I passing through the arc electromagnet according to the Pareto optimal solution includes the following steps: S2.1 Establishing the electromagnetic attraction force requirement model for the arc-shaped electromagnet: Based on the mass of the moving trolley, the turning radius, and the friction coefficient, determine the system constant k, and obtain the theoretical electromagnet attraction force F. req =k·V 2 ; S2.2 Construct a multi-objective optimization function, which includes two objectives: the first objective is to maximize the speed performance min(-V); the second objective is to minimize the actual electromagnet attraction force F. n Compared with the theoretical value F req deviation min|F n -kV 2 |; S2.3, Set constraints: α·k·V 2 ≤F n ≤F max And V∈[V min V max ]; where α represents the safety factor, α∈(0.8,0.95); V min V represents the minimum constrained speed of the moving trolley. max This indicates the maximum constrained speed of the moving trolley; S2.

4. Use the NSGA-II multi-objective evolutionary algorithm to solve the multi-objective optimization function described in step S2.2, and generate the Pareto optimal solution (V). * F n * According to the Pareto optimal solution, the current I passing through the arc electromagnet is dynamically adjusted through the H-bridge drive circuit so that the current I passing through the arc electromagnet satisfies: Where d represents the distance between the electromagnet and the moving core; F a The value represents the centripetal force acting on the moving carriage; μ0 represents the vacuum permeability; N represents the number of turns of the coil inside the electromagnet; and A0 represents the cross-sectional area of ​​the magnetic pole.

Images