An electric control device for a mobile robot

Abstract

The utility model relates to AGV dolly technical field especially relates to a kind of electric control device of mobile robot hoisting. Including: three groups of suspension oil cylinder and the piston rod embedded in suspension oil cylinder, respectively corresponding the hoisting control of robot left front, right front, rear side;Hydraulic pump station, constitute circulation oil circuit between with suspension oil cylinder, provide driving force for piston rod in suspension oil cylinder extension;Displacement sensor, set up on suspension oil cylinder, for sensing the position of piston rod in suspension oil cylinder;Inclination sensor, set up on the lifting workbench of installation robot, for sensing levelness.When AGV transfer, move horizontally, cross road barrier, oil circuit will flow between different wheel groups, through the telescopic cooperation of suspension oil cylinder and piston rod, reduce the attitude change amplitude of AGV, maximum limit guarantee product attitude does not obviously change, ensure that product is stable and reliable on rotating support mechanism, does not appear inclination, bounce, shift and other security risks.

Description

Technical Field

[0001] This utility model relates to the field of AGV (Automated Guided Vehicle) technology, and in particular to an electronic control device for lifting a mobile robot. Background Technology

[0002] Automated Guided Vehicles (AGVs), as intelligent material handling equipment, have been widely used in warehousing and logistics, intelligent manufacturing, and flexible production lines. Among them, the lifting AGV achieves the vertical movement of the carrying platform through a lifting mechanism, thereby completing operations such as picking up and placing goods, docking and assembly. It has high requirements for lifting accuracy, load capacity and response speed.

[0003] Currently, the lifting mechanisms of traditional mobile robots mostly employ motor-screw or cylinder-driven methods. The motor-screw structure converts linear motion into linear motion by driving a screw with a rotary motor. While offering relatively high control precision, it has limited load capacity (typically not exceeding 500 kg) and slow lifting speed. Furthermore, prolonged use can lead to decreased precision due to wear and tear on mechanical transmission components. While the cylinder-driven method is simple in structure, it relies on an external air source, resulting in high power consumption, significant noise, low control precision, and poor stability, making it unsuitable for high-precision operating environments.

[0004] While hydraulic lifting systems offer advantages such as high load capacity and stability in industrial fixed equipment, their direct application in the field of mobile robots, especially AGV equipment with high requirements for dynamic response performance and control precision, presents significant drawbacks. Electro-hydraulic control systems suffer from problems such as response lag, strong nonlinearity, and complex precision adjustment, making it difficult to achieve fast, stable, and high-precision lifting control, thus limiting the application of hydraulic technology in intelligent mobile robots.

[0005] Therefore, this utility model provides an electronic control device for lifting a mobile robot, so as to achieve stable lifting and lowering of the robot. Utility Model Content

[0006] The purpose of this invention is to solve the problems existing in the prior art by proposing an electronic control device for lifting a mobile robot.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: An electronic control device for lifting a mobile robot includes: The three sets of suspension cylinders and the piston rods embedded in the suspension cylinders correspond to the lifting control of the robot's left front, right front, and rear sides, respectively. The hydraulic pump station forms a circulating oil circuit with the suspension cylinder, providing driving force to the piston rod as it extends in the suspension cylinder. A displacement sensor, installed on the suspension cylinder, is used to sense the position of the piston rod inside the suspension cylinder; The tilt sensor is installed on the lifting platform where the robot is mounted to sense the levelness.

[0008] Preferably, the circulating oil circuit includes an inlet flow control valve connected to the outlet of the modular hydraulic pump station, an inlet electric regulating valve connected to the outlet of the inlet flow control valve, an outlet of the inlet electric regulating valve connected to the inlet of the suspension cylinder, an outlet of the suspension cylinder connected to a return electric regulating valve, an outlet of the return electric regulating valve connected to a return flow control valve, and an outlet of the return flow control valve connected to the inlet of the modular hydraulic pump station, thus forming a circulating oil circuit.

[0009] Preferably, the hydraulic pump station includes an oil tank, a gear pump, and an electric motor. The electric motor provides driving force to the gear pump. The oil outlet of the oil tank is connected to the oil inlet of the gear pump, and the oil outlet of the gear pump is connected to the oil inlet of the oil flow control valve.

[0010] Preferably, the three sets of circulating oil circuits share a single oil tank.

[0011] Preferably, a filter is provided between the oil inlet of the gear pump and the oil tank.

[0012] Preferably, a check valve is provided between the oil outlet of the gear pump and the oil inlet flow control valve.

[0013] Preferably, a pressure reducing valve is provided between the oil outlet of the gear pump and the one-way valve.

[0014] Preferably, it also includes a pressure sensor disposed in the circulating oil circuit for sensing the oil circuit pressure.

[0015] Compared with the prior art, this utility model provides an electronic control device for lifting a mobile robot, which has the following advantages: 1. This utility model combines hydraulic circuits of different wheels. When the AGV is transporting, moving laterally, or crossing road obstacles, the oil flows between different wheel sets. Through the extension and retraction of the suspension cylinder and piston rod, the AGV's posture change range is reduced, ensuring that the product's posture does not change significantly to the maximum extent. This ensures that the product is stable and reliable on the rotating support mechanism, without any safety hazards such as tilting, jumping, or swaying.

[0016] 2. This utility model uses displacement sensors and other sensors to sense the vehicle's operating status in real time, thereby controlling the opening and closing of the corresponding side hydraulic circuit to adjust the extension and retraction of the telescopic rod within the suspension cylinder, and thus adjusting the vehicle's status in real time.

[0017] Other advantages, objectives and features of this invention will be set forth in part in the description which follows; and in part will be apparent to those skilled in the art upon examination of the following description; or may be taught from practice of this invention. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the hydraulic control system with three sets of oil circuits according to this utility model.

[0019] Figure 2 This is a schematic diagram of the hydraulic control system of a single oil circuit according to this utility model.

[0020] Figure 3 Comparison of the vehicle's undulation state when passing through obstacles with and without the oil circuit of this scheme (gray) set up.

[0021] In the diagram: 1. Oil tank; 2. Filter; 3. Gear pump; 4. Electric motor; 5. Pressure reducing valve; 6. Inlet flow control valve; 7. Inlet electric regulating valve; 8. Return electric regulating valve; 9. Return flow control valve. Detailed Implementation

[0022] The following will refer to the appendix in the embodiments of this utility model. Figure 1-2 The technical solutions in the embodiments of this utility model will be clearly and completely described. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0023] Example 1: A conventional AGV (Automated Guided Vehicle) includes a chassis, frame, navigation system, and power system. The chassis is the basic component of the AGV, housing drive wheels, typically driven by an electric motor 4, which is the power source for the AGV's movement. Steering is achieved through differential speed coordination between the electric motors 4 on different drive wheels. The frame, usually supported by steel or aluminum alloy, serves as the foundation for the vehicle to carry goods. The navigation system mostly uses sensors such as LiDAR and cameras to determine the AGV's position and path. The power system provides energy to the AGV, and the battery pack is rechargeable.

[0024] When using AGVs, they mostly move under the goods, then lift the goods and carry them for positioning and transfer. To achieve this lifting, a lifting mechanism is necessary. Traditional lifting mechanisms, such as electric screw lifts, are slow, and scissor lifts are bulky, both having their limitations.

[0025] Therefore, this solution provides a hydraulic lifting structure and a matching electrical control device, including: (1) Suspension cylinder and piston rod embedded in suspension cylinder. The suspension cylinder is mounted on the drive wheel system truss, and the top of the piston rod is hinged to the chassis through pre-drilled bolt holes. The piston rod is driven to rise and fall within the suspension cylinder, thereby realizing the lifting operation of the robot's (AGV trolley) lifting platform (i.e., the frame), which constitutes the lifting drive source of the robot's lifting platform.

[0026] (2) The hydraulic pump station forms a circulating oil circuit with the suspension cylinder to provide driving force for the piston rod as it extends in the suspension cylinder.

[0027] (3) Displacement sensor, which is installed on the suspension cylinder, is used to sense the position of the piston rod in the suspension cylinder and also to sense the lifting height of the piston rod.

[0028] (4) Inclination sensor, which is installed on the lifting workbench of the robot to sense the levelness of the lifting surface of the goods.

[0029] In this embodiment, the hydraulic pump station includes an oil tank 1, a gear pump 3, and an electric motor 4 mounted on a chassis. The oil tank 1 stores hydraulic oil and has an oil inlet and an oil outlet for adding new oil and discharging waste oil, respectively. The gear pump 3 consists of a pump cylinder, front and rear covers that are detachably mounted with bolts, two gears, and corresponding gear shafts. The output end of the electric motor 4 is connected to the extended end of the gear shaft via a coupling, providing power to the gear pump 3. The oil outlet (oil outlet pipe) of the oil tank 1 is connected to the oil inlet of the pump cylinder via a pipe. The electric motor 4 drives the gear shaft to rotate, and the hydraulic oil in the oil tank 1 is extracted and transported by the change and movement of the working volume formed between the pump cylinder and the meshing gears. The electric motor 4 is a geared motor, making it easier to adjust the pressure increase speed.

[0030] In this embodiment, the circulating oil circuit includes an inlet flow control valve 6, an inlet electric regulating valve 7, a return electric regulating valve 8, and a return flow control valve 9. The pump cylinder outlet of the gear pump 3 is connected to the inlet of the inlet flow control valve 6, the outlet of the inlet flow control valve 6 is connected to the inlet of the inlet electric regulating valve 7, the outlet of the inlet electric regulating valve 7 is connected to the inlet of the suspension cylinder, the outlet of the suspension cylinder is connected to the inlet of the return electric regulating valve 8, the outlet of the return electric regulating valve 8 is connected to the inlet of the return flow control valve 9, and the outlet of the return flow control valve 9 is connected to the inlet of the oil tank 1, thus forming a circulating oil circuit.

[0031] In this embodiment, the AGV is equipped with a controller, whose electronic control unit uses a Delta 15MC11T CPU and a PID closed-loop control algorithm. PID control, or proportional-integral-derivative control, combines the advantages of proportional action (timely and rapid), integral action (eliminating steady-state error), and derivative action (leading control). When a step deviation occurs, the derivative immediately and significantly controls this abrupt change in deviation; the proportional action also simultaneously eliminates the deviation, reducing its magnitude. Our finished AGV uses the existing structure of this control system without modifying the control itself, but rather utilizes the inherent characteristics and functions of the control system.

[0032] In this embodiment, the circulating oil circuit is provided in three sets, corresponding to the lifting control of the robot's left front, right front, and rear sides, respectively. The three sets of circulating oil circuits share a single oil tank 1, integrating the equipment and reducing the external space occupied.

[0033] Based on the above technical solution: During normal operation, the motor 4 is off, and the oil inlet flow control valve 6, the oil inlet electric regulating valve 7, the oil return flow control valve 9, and the oil return electric regulating valve 8 are all closed. The hydraulic oil content in the suspension cylinder is low, causing the piston rod to be in a retracted state.

[0034] When the robot lifts the cargo, the motor 4 drives the gear pump 3 to start, drawing hydraulic oil from the oil tank 1 and delivering it. The inlet flow control valve 6 and the electric inlet regulating valve 7 of the three oil circuits open, allowing hydraulic oil to flow into the suspension cylinders, thus lifting the piston rod. The piston rod then lifts the lifting surface, pressing it against the lower end of the cargo, suspending it for transport. Throughout the lifting process, the tilt sensor continuously monitors the levelness of the lifting surface, controlling the inlet flow control valve 6 and the electric inlet regulating valve 7 to balance the hydraulic oil input to the three suspension cylinders, ensuring a level lifting surface and preventing slippage due to tilt. After lifting the material, the inlet flow control valve 6, the electric inlet regulating valve 7, and the motor 4 close, leaving the hydraulic oil in the suspension cylinders. The piston rod remains stably lifted, achieving smooth material lifting and transport. After being moved to the designated area, when it needs to fall back, the electric return oil regulating valve 8 and the return oil flow control valve 9 are opened. Under the action of the vehicle's own weight, some of the hydraulic oil in the suspension cylinder is squeezed out through the oil outlet of the hydraulic cylinder and flows back into the oil tank 1 through the electric return oil regulating valve 8 and the return oil flow control valve 9. When the hydraulic oil in the suspension oil tank 1 decreases, the piston rod falls back, thereby driving the lifting surface to fall back.

[0035] When passing obstacles, such as the left front wheel, normally the wheel running over the obstacle would cause the vehicle body on that side to lift, resulting in a tilt. This device reacts immediately through control: based on information from the tilt sensor, the electric return oil regulating valve 8 and the return oil flow control valve 9 of the corresponding hydraulic circuit on the left side of the vehicle open, causing some hydraulic oil in the suspension cylinder to flow back into the oil tank 1. At this time, the piston rod on the left front side of the vehicle body falls, thereby causing the left front side of the vehicle body to fall, balancing the lift height when running over the obstacle and keeping the vehicle body support surface as stable and level as possible. After passing the obstacle, the electric inlet oil regulating valve 7, the inlet oil flow control valve 6, and the electric motor 4 of the left front side hydraulic circuit open, injecting some hydraulic oil into the left front side suspension cylinder, so that the vehicle body is on a flat surface, and the left front side returns to level.

[0036] Similarly, when passing through a ditch, such as when the left front wheel passes through a ditch, this device will open the oil inlet flow control valve 6, the oil inlet electric regulating valve 7, and the electric motor 4 of the corresponding oil circuit on the left front, and will add hydraulic oil to the suspension cylinder on the left front, so that the piston rod in the suspension cylinder on the left front side rises to balance the drop distance of the vehicle body and ensure that the lifting surface is horizontal.

[0037] By combining the hydraulic circuits of different wheels, when the AGV is transporting, moving laterally, or crossing road obstacles, the hydraulic circuits will flow between different wheel sets. Through the extension and retraction of the suspension cylinder and piston rod, the amplitude of the AGV's posture change is reduced, ensuring that the product's posture does not change significantly to the maximum extent. This ensures that the product is stable and reliable on the rotating support mechanism, without any safety hazards such as tilting, jumping, or swaying.

[0038] In this embodiment, a filter 2 is provided between the oil inlet of the gear pump 3 and the oil tank 1 to prevent impurities generated in the circulating hydraulic oil from flowing into the gear pump 3, causing the meshing gears to jam and affecting the transmission stability; at the same time, it prevents impurities from entering the oil circuit and causing oil circuit blockage.

[0039] In this embodiment, a check valve is provided between the oil outlet of the gear pump 3 and the oil inlet flow control valve 6 to prevent the hydraulic oil output by the gear pump 3 from flowing back under pressure.

[0040] In this embodiment, a pressure sensor is also provided in the circulating oil circuit to sense the oil circuit pressure. A pressure reducing valve 5 is provided between the oil outlet of the gear pump 3 and the check valve to automatically maintain a stable hydraulic oil outlet pressure.

[0041] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

[0042] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An electric control device for a mobile robot hoist, characterized by, include: The three sets of suspension cylinders and the piston rods embedded in the suspension cylinders correspond to the lifting control of the robot's left front, right front, and rear sides, respectively. The hydraulic pump station and the suspension cylinder form a circulating oil circuit to provide driving force for the piston rod as the suspension cylinder extends. A displacement sensor, installed on the suspension cylinder, is used to sense the position of the piston rod inside the suspension cylinder; The tilt sensor is installed on the lifting platform where the robot is mounted to sense the levelness.

2. The electronic control device for lifting a mobile robot according to claim 1, characterized in that, The circulating oil circuit includes an inlet flow control valve (6) that is connected to the outlet of the modular hydraulic pump station. The outlet of the inlet flow control valve (6) is connected to an inlet electric regulating valve (7). The outlet of the inlet electric regulating valve (7) is connected to the inlet of the suspension cylinder. The outlet of the suspension cylinder is connected to a return electric regulating valve (8). The outlet of the return electric regulating valve (8) is connected to a return flow control valve (9). The outlet of the return flow control valve (9) is connected to the inlet of the modular hydraulic pump station, thus forming a circulating oil circuit.

3. The electronic control device for lifting a mobile robot according to claim 2, characterized in that, The hydraulic pump station includes an oil tank (1), a gear pump (3), and an electric motor (4). The electric motor (4) provides driving force to the gear pump (3). The oil outlet of the oil tank (1) is connected to the oil inlet of the gear pump (3), and the oil outlet of the gear pump (3) is connected to the oil inlet of the oil flow control valve (6).

4. The electronic control device for lifting a mobile robot according to claim 3, characterized in that, The three sets of circulating oil circuits share one oil tank (1).

5. The electronic control device for lifting a mobile robot according to claim 3, characterized in that, A filter (2) is provided between the oil inlet of the gear pump (3) and the oil tank (1).

6. The electronic control device for lifting a mobile robot according to claim 3, characterized in that, A check valve is provided between the oil outlet of the gear pump (3) and the oil inlet flow control valve (6).

7. The electronic control device for lifting a mobile robot according to claim 3, characterized in that, A pressure reducing valve (5) is provided between the oil outlet of the gear pump (3) and the check valve.

8. The electronic control device for lifting a mobile robot according to claim 1, characterized in that, It also includes a pressure sensor installed in the circulating oil circuit to sense the oil circuit pressure.

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