A closed-loop synchronous control system for synchronous motor control

Abstract

This utility model discloses a closed-loop synchronous control system controlled by a synchronous motor, including an AGV body, multiple hydraulic cylinders, an oil tank, a synchronous motor, a power unit, a driver, multiple hydraulically controlled check valves, a first solenoid directional valve, a second solenoid directional valve, and a controller. The power unit drives the pump outlet block via a motor, and the flow is evenly distributed to each hydraulic cylinder via the synchronous motor to achieve the lifting action. The first and second solenoid directional valves control the oil supply direction and the opening and closing of the hydraulically controlled check valves, respectively, working in conjunction with the hydraulically controlled check valves to achieve pressure holding and lowering functions. The controller collects data in real time through displacement sensors on the hydraulic cylinders, driving the solenoid directional valves to fine-tune the flow, forming a closed-loop control. The hardware closed-loop architecture improves synchronization accuracy, adapts to off-center load conditions, and expands the lifting speed range by adding a throttle valve, while also being relatively lower in cost and easier to maintain. It can be widely used in AGV lifting platforms, industrial lifting equipment, and other scenarios.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic applications, and more specifically, to a closed-loop synchronous control system for synchronous motor control. Background Technology

[0002] In hydraulic applications, the accuracy and stability of synchronous lifting systems are key technical indicators. While existing open-loop control systems using synchronous motors are lower in cost, they only distribute flow through mechanical structures and cannot compensate for displacement deviations caused by off-center loads in real time. Synchronization accuracy is typically below ±10mm, and they have weak resistance to off-center loads, easily accumulating errors and even failing to function properly under unbalanced loads. Closed-loop control systems based on proportional valves can achieve high-precision synchronization (within ±2mm) through real-time flow regulation, but their cost is 3-5 times higher than synchronous motor solutions. Furthermore, proportional valves have high requirements for hydraulic oil cleanliness and are complex to maintain, making them difficult to adopt in cost-sensitive industrial scenarios. In addition, traditional systems lack flexible speed adjustment mechanisms, limiting the lifting speed range (typically below 20mm / s) and failing to adapt to efficiency requirements under different loads.

[0003] How to invent a closed-loop synchronous control system for synchronous motor control to improve these problems has become an urgent problem to be solved by those skilled in the art. Utility Model Content

[0004] To overcome the above shortcomings, this utility model provides a closed-loop synchronous control system controlled by a synchronous motor, which aims to improve the problems of low accuracy, poor resistance to off-center load, high cost, complex maintenance and insufficient speed adaptability of existing synchronous lifting systems.

[0005] This invention is implemented as follows: a closed-loop synchronous control system for synchronous motor control, comprising: AGV vehicle body; Multiple hydraulic cylinders are mounted on the AGV body; The oil tank is connected to the oil inlet of the synchronous motor via an oil pipe; A synchronous motor, wherein the oil inlet of the synchronous motor is connected to the oil tank; The power unit includes a motor and a pump outlet block. The motor is connected to the pump outlet block, and the pump outlet block forms an oil circuit circulation with the synchronous motor and the oil tank through an oil pipe. A driver, which is electrically connected to the power unit; Multiple hydraulically controlled check valves, each of which is connected to the corresponding rodless chamber inlet of the hydraulic cylinder via an oil pipe; The first electromagnetic directional valve is installed in the oil supply line of the synchronous motor and is connected via an oil pipe. The second electromagnetic directional valve is connected to the hydraulic control check valve control oil circuit via an oil pipe; The controller is electrically connected to the plurality of hydraulic cylinders, the first solenoid directional valve, and the second solenoid directional valve.

[0006] In a preferred embodiment of this utility model, the power unit further includes an overflow valve, which is connected to the oil outlet pipe of the pump outlet block via an oil pipe.

[0007] In a preferred embodiment of this utility model, a displacement sensor is installed on the hydraulic cylinder, and the displacement sensor is electrically connected to the controller.

[0008] In a preferred embodiment of this utility model, a throttle valve is superimposed on the oil outlet of the first electromagnetic directional valve, and the throttle valve is connected to the first electromagnetic directional valve through an oil pipe.

[0009] In a preferred embodiment of this utility model, the controller is a PID controller, which is electrically connected to the plurality of hydraulic cylinders, the first solenoid directional valve, and the second solenoid directional valve.

[0010] The beneficial effects of this utility model are as follows: The closed-loop synchronous control system for synchronous motor control obtained through the above design uses a displacement sensor to collect data in real time and drive the electromagnetic directional valve to fine-tune the flow rate, improving synchronization accuracy and effectively handling off-center load conditions. The hydraulically controlled check valve enables pressure holding at any position, enhancing system safety. The overall structure uses standardized hydraulic components, and modular parts such as the electromagnetic directional valve can be quickly replaced during maintenance, reducing operating costs. This comprehensively improves synchronous control performance and can be widely applied in AGV lifting platforms, industrial lifting equipment, and other scenarios. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the overall structure provided by an embodiment of the present invention.

[0013] In the diagram: 1. AGV body; 2. Hydraulic cylinder; 3. Oil tank; 4. Synchronous motor; 5. Motor; 6. Pump outlet block; 7. Driver; 8. Hydraulic control check valve; 9. First solenoid directional valve; 10. Second solenoid directional valve. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0015] Please see Figure 1 This utility model provides a technical solution: a closed-loop synchronous control system for synchronous motor control, comprising: AGV vehicle body 1; Multiple hydraulic cylinders 2 are mounted on the AGV body 1; Oil tank 3 is connected to the oil inlet of synchronous motor 4 via an oil pipe; Synchronous motor 4, the oil inlet of synchronous motor 4 is connected to oil tank 3; The power unit includes a motor 5 and a pump outlet block 6. The motor 5 is connected to the pump outlet block 6. The pump outlet block 6 forms an oil circuit circulation with the synchronous motor 4 and the oil tank 3 through an oil pipe. Driver 7 is electrically connected to the power unit; Multiple hydraulic control check valves 8, each hydraulic control check valve 8 is connected to the oil inlet of the rodless chamber of the corresponding hydraulic cylinder 2 through an oil pipe; The first electromagnetic reversing valve 9 is installed in the oil supply line of the synchronous motor 4 and is connected via an oil pipe. The second electromagnetic directional valve 10 is connected to the hydraulic control check valve 8 via an oil pipe to control the oil circuit. The controller is electrically connected to multiple hydraulic cylinders 2, the first solenoid directional valve 9, and the second solenoid directional valve 10.

[0016] Furthermore, the power unit also includes an overflow valve, which is connected to the oil outlet line of the pump outlet block 6 via an oil pipe.

[0017] The relief valve can be either direct-acting or pilot-operated. It is installed in parallel with the main oil outlet line of the pump outlet block 6 and the oil tank 3 via an oil pipe. Its inlet is directly connected to the outlet of the pump outlet block 6, and the outlet is connected to the oil tank 3. When the system pressure exceeds the relief valve's set value, the valve core opens to overflow, and the oil flows back to the oil tank 3 through the oil pipe. The hardware redundancy structure ensures system safety and avoids pressure over-limit caused by sudden load changes or motor malfunction, complying with industrial equipment safety standards.

[0018] Furthermore, a displacement sensor is installed on the hydraulic cylinder 2, and the displacement sensor is electrically connected to the controller.

[0019] The displacement sensor, employing either a magnetostrictive or laser displacement sensor, is mounted on the piston rod end or the outer side of the cylinder (e.g., fixed via a U-shaped bracket). Its sensing end is aligned with the piston rod end and connected to the controller's analog input module via a signal line, outputting a position signal in real time. This structured position feedback device enables the controller to monitor the height difference between the hydraulic cylinders in real time, providing a data basis for fine-tuning the flow rate of the electromagnetic directional valve and improving synchronization accuracy.

[0020] Furthermore, a throttle valve is superimposed on the oil outlet of the first solenoid directional valve 9, and the throttle valve is connected to the first solenoid directional valve 9 through an oil pipe.

[0021] The throttle valve is an adjustable flow valve, installed via threads or flanges on the oil pipe between the outlet of the first solenoid directional valve 9 and the inlet of the synchronous motor 4. Its valve core opening can be adjusted manually via a knob or electric actuator. When the solenoid directional valve is open, the throttle valve remains partially open, allowing pressurized oil to continue supplying the hydraulic cylinder after throttling, reducing speed fluctuations caused by momentary flow interruptions. This hardware stacking structure increases the system's allowable lifting speed limit, adapting to speed requirements under different load scenarios and expanding its application range.

[0022] Furthermore, the controller is a PID controller, which is electrically connected to multiple hydraulic cylinders 2, the first solenoid directional valve 9, and the second solenoid directional valve 10.

[0023] The controller is a hardware-integrated PID control module. Its input is electrically connected to the displacement sensors of multiple hydraulic cylinders 2, and its output is electrically connected to the four fine-tuning solenoid valves of the first solenoid directional valve 9. The controller has a built-in arithmetic circuit that calculates and outputs pulse signals based on the real-time displacement difference to control the on / off frequency of the corresponding solenoid directional valves. Through a standardized closed-loop control hardware architecture, and utilizing the automatic adjustment characteristics of the PID algorithm, it can dynamically compensate for flow deviations caused by off-center loads without manual intervention, reducing costs while maintaining synchronization accuracy.

[0024] Working principle: The AGV body 1 is equipped with multiple hydraulic cylinders 2. The motor 5 in the power unit drives the hydraulic pump in the pump outlet block 6, which delivers the hydraulic oil from the oil tank 3 to the synchronous motor 4 through the oil pipe. The synchronous motor 4 distributes the input flow evenly to multiple oil outlets, which supply the rodless chamber of each hydraulic cylinder 2 through the oil pipe, thereby realizing the lifting action. The first electromagnetic reversing valve 9 is set in the oil supply line of the synchronous motor 4 to control the oil supply direction of the synchronous motor 4: when lifting is required, the first electromagnetic reversing valve 9 opens the oil circuit between the pump outlet block 6 and the oil inlet of the synchronous motor 4, and the pressurized oil drives the synchronous motor 4 to evenly distribute the flow to each hydraulic cylinder 2; when lowering is required, the first electromagnetic reversing valve 9 opens the oil circuit between the pump outlet block 6 and the rod chamber of the hydraulic cylinder 2, and the pressurized oil directly enters the rod chamber to drive the hydraulic cylinder to retract. The hydraulically controlled check valve 8 installed at the oil inlet of the rodless chamber of each hydraulic cylinder 2 is closed during pressure holding, locking the position of the hydraulic cylinder. During descent, the second solenoid directional valve 10 opens the control oil circuit, inputting pressurized oil into the pilot chamber of the hydraulically controlled check valve 8, forcibly opening the check valve to allow the oil in the rodless chamber to flow back to the oil tank 3. The displacement sensor on the piston rod of the hydraulic cylinder 2 collects position data in real time and feeds it back to the controller. When the displacement difference of each hydraulic cylinder exceeds the set value, the controller outputs a signal to control the on / off of the fine-tuning solenoid valve of the first solenoid directional valve 9, adjusting the oil supply of the corresponding hydraulic cylinder 2 to compensate for the deviation. The throttle valve superimposed on the oil outlet of the first solenoid directional valve 9 can adjust the opening degree, reducing flow loss and reducing the frequency of solenoid valve use, thus expanding the applicable speed range of the system. The relief valve is connected in parallel between the oil outlet line of the pump outlet block 6 and the oil tank 3. When the system pressure exceeds the set value, the relief valve opens to prevent the pressure from exceeding the limit and damaging the components. Through the coordinated operation of the aforementioned components, closed-loop control of synchronous lifting or lowering of multiple cylinders is achieved, meeting the high precision and anti-eccentric load requirements of mobile energy storage charging vehicles in various scenarios.

[0025] It should be noted that the specific models and specifications of the hydraulic cylinder 2, synchronous motor 4, motor 5, pump outlet block 6, driver 7, hydraulic control check valve 8, first solenoid directional valve 9, and second solenoid directional valve 10 need to be selected and determined according to the actual specifications of the device. The specific selection and calculation method adopts the existing technology in this field, so it will not be described in detail.

[0026] The power supply and operating principle of the hydraulic cylinder 2, synchronous motor 4, electric motor 5, pump outlet block 6, driver 7, hydraulic control check valve 8, first solenoid directional valve 9, and second solenoid directional valve 10 are clear to those skilled in the art and will not be described in detail here.

[0027] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A closed loop synchronous control system for synchronous motor control, characterized by, include: AGV vehicle body; Multiple hydraulic cylinders are mounted on the AGV body; The oil tank is connected to the oil inlet of the synchronous motor via an oil pipe; A synchronous motor, wherein the oil inlet of the synchronous motor is connected to the oil tank; The power unit includes a motor and a pump outlet block. The motor is connected to the pump outlet block, and the pump outlet block forms an oil circuit circulation with the synchronous motor and the oil tank through an oil pipe. A driver, which is electrically connected to the power unit; Multiple hydraulically controlled check valves, each of which is connected to the corresponding rodless chamber inlet of the hydraulic cylinder via an oil pipe; The first electromagnetic directional valve is installed in the oil supply line of the synchronous motor and is connected via an oil pipe. The second electromagnetic directional valve is connected to the hydraulic control check valve control oil circuit via an oil pipe; The controller is electrically connected to the plurality of hydraulic cylinders, the first solenoid directional valve, and the second solenoid directional valve.

2. The closed loop synchronous control system with synchronous motor control of claim 1, wherein: The power unit also includes an overflow valve, which is connected to the oil outlet line of the pump outlet block via an oil pipe.

3. The closed loop synchronous control system with synchronous motor control of claim 1, wherein: A displacement sensor is installed on the hydraulic cylinder, and the displacement sensor is electrically connected to the controller.

4. The closed loop synchronous control system of claim 1, wherein: A throttle valve is superimposed on the oil outlet of the first electromagnetic directional valve, and the throttle valve is connected to the first electromagnetic directional valve through an oil pipe.

5. The closed loop synchronous control system of claim 1, wherein: The controller is a PID controller, which is electrically connected to multiple hydraulic cylinders, a first solenoid directional valve, and a second solenoid directional valve.

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