A heavy-loaded robotic arm potential energy recovery system and control method

Abstract

The present invention discloses a heavy-duty mechanical arm potential energy recovery system and control method, specifically relating to the technical field of hydraulic excavators. The system includes a hydraulic pump, a three-position four-way solenoid valve, a three-chamber hydraulic cylinder, a first pressure sensor, a second pressure sensor, a first proportional valve, a second proportional valve, a third proportional valve, an accumulator, a rangefinder, and a controller. The hydraulic pump is connected to the three-position four-way solenoid valve, one outlet of which is connected to a rod chamber and a first pressure sensor is provided on a pipeline, while the other outlet is connected to a rodless chamber. The first proportional valve and the second proportional valve are both connected to the accumulator chamber, a second pressure sensor is provided on a pipeline connecting the first proportional valve and the accumulator, the second proportional valve is connected and communicated with an oil tank, the oil inlet of the third proportional valve is connected to the hydraulic pump, and the oil outlet is connected to the accumulator, and a rangefinder is installed on the bucket. The present invention can automatically switch working states, reduce the misjudgment rate, improve the overall machine controllability, and increase the potential energy recovery rate.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic excavators, and in particular to a heavy-load mechanical arm potential energy recovery system and a control method. Background Art

[0002] Hydraulic excavators are characterized by high efficiency, good adaptability to working conditions, and a wide range of applications. However, the load inertia of the hydraulic excavator's arm actuator is large, resulting in severe energy loss during the frequent lifting and lowering of materials. Currently, the most efficient and simple energy recovery method for hydraulic excavators is to use an accumulator as an energy storage element and replace the original two-chamber hydraulic cylinder with a three-chamber hydraulic cylinder to recover the potential energy of the excavator's arm. However, when the special working condition of supporting the vehicle is achieved by extending and adjusting the position and posture of the arm, the accumulator connected to the energy storage chamber is always pressurized. Therefore, the arm faces significant resistance during the descent process, often causing the rod chamber pressure of the three-chamber hydraulic cylinder to reach the system's overflow pressure value, causing the excavator to lose its original working ability and seriously affecting the controllability of the entire machine. Summary of the Invention

[0003] The purpose of the present invention is to provide a heavy-duty robotic arm potential energy recovery system and control method to solve the problems existing in the above-mentioned prior art, which can automatically switch working states, reduce the misjudgment rate, improve the controllability of the whole machine, and improve the potential energy recovery rate.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a heavy-duty robotic arm potential energy recovery system, comprising an oil tank, a hydraulic pump, a power element, a three-position four-way solenoid valve, a three-chamber hydraulic cylinder, a first pressure sensor, a second pressure sensor, a first proportional valve, a second proportional valve, a third proportional valve, an accumulator, a rangefinder and a controller; the power element is transmission-connected to the hydraulic pump, the oil inlet of the hydraulic pump is connected and communicated with the oil tank, the oil outlet of the hydraulic pump is connected and communicated with the oil inlet of the three-position four-way solenoid valve, the first oil outlet of the three-position four-way solenoid valve is connected and communicated with the rod cavity of the three-chamber hydraulic cylinder, and the first pressure sensor is provided on the pipeline connecting the first oil outlet of the three-position four-way solenoid valve and the rod cavity of the three-chamber hydraulic cylinder, and the second oil outlet of the three-position four-way solenoid valve is connected to the rodless cavity of the three-chamber hydraulic cylinder and are connected, the oil inlet of the first proportional valve and the oil inlet of the second proportional valve are both connected to and connected with the energy storage chamber of the three-chamber hydraulic cylinder, the oil outlet of the first proportional valve is connected to and connected with the accumulator, the second pressure sensor is provided on the pipeline connecting the oil outlet of the first proportional valve and the accumulator, the oil outlet of the second proportional valve is connected to and connected with the oil tank, the accumulator is connected to and connected with the oil outlet of the third proportional valve, the oil inlet of the third proportional valve is connected to and connected with the hydraulic pump, the rangefinder is fixedly installed on the bucket, the rangefinder is used to detect the distance between the bucket and the ground, the first pressure sensor, the second pressure sensor, the first proportional valve, the second proportional valve, the third proportional valve and the rangefinder are all connected with the controller signal.

[0006] Preferably, a flow direction check valve is provided on the pipeline connecting the oil outlet of the third proportional valve and the accumulator.

[0007] Preferably, it further comprises a camera, which is fixedly mounted on the bucket and is connected to the controller signal.

[0008] Preferably, it further includes an overflow valve, the accumulator is connected and communicated with the oil tank, and the overflow valve is provided on the pipeline communicating between the accumulator and the oil tank.

[0009] The present invention also provides a control method using the heavy-loaded robotic arm potential energy recovery system, including a robotic arm descending working condition and a robotic arm ascending working condition;

[0010] Robotic arm descending working condition:

[0011] Based on the pressure information of the rod chamber of the three-chamber hydraulic cylinder monitored by the first pressure sensor and the distance information from the bucket to the excavation surface collected by the rangefinder and received by the controller, it is jointly determined whether the boom is in a working condition requiring the boom to be lowered; only when the pressure signal and the distance signal simultaneously meet the lowering working condition, the controller obtains the working condition information that the robotic arm is in the robotic arm lowering condition; the controller controls the closing of the first proportional valve to cut off the passage between the energy storage chamber of the three-chamber hydraulic cylinder and the accumulator, and simultaneously opens the second proportional valve to connect the energy storage chamber of the three-chamber hydraulic cylinder with the oil tank, thereby unloading the energy storage chamber of the three-chamber hydraulic cylinder, thereby allowing the robotic arm to be lowered smoothly;

[0012] Working condition of the robotic arm descending and then ascending:

[0013] After the excavator is in the working condition of lowering the mechanical arm, the controller continues to collect and analyze the pressure signal and the distance signal. When the controller determines that the preset conditions for the raising of the mechanical arm are met, the controller opens the first proportional valve to connect the energy storage chamber of the three-chamber hydraulic cylinder with the passage of the accumulator, and at the same time closes the second proportional valve to cut off the passage between the energy storage chamber of the three-chamber hydraulic cylinder and the oil tank. The hydraulic oil in the accumulator enters the energy storage chamber of the three-chamber hydraulic cylinder through the first proportional valve to realize the raising and merging of the mechanical arm; when the pressure monitored by the second pressure sensor received by the controller is insufficient, the controller controls the opening of the third proportional valve to realize pressure closed-loop control to ensure that the excavator can maintain normal operation in the energy recovery mode.

[0014] Compared with the prior art, the present invention has achieved the following technical effects:

[0015] The present invention provides a heavy-duty mechanical arm potential energy recovery system and control method. The working state of the excavator can be measured in real time by a first pressure sensor and a rangefinder, and the collected signal is transmitted to a controller. The controller analyzes and judges, thereby realizing automatic identification of the working condition of the excavator. Then, the controller completes automatic switching of a multi-mode control system by controlling the opening of a first proportional valve and a second proportional valve, effectively avoiding misjudgment caused by sudden signal changes. The controller can accurately identify the working state of the excavator and automatically control the switching of the working mode to ensure the timeliness and smoothness of the switching. In the boom lifting stage, the signal collected by the second pressure sensor is transmitted to the controller, a pressure closed-loop control strategy is set, and the opening of the third proportional valve is controlled by the controller output signal to realize a pressure closed-loop, thereby ensuring the pressure stability of the entire system loop. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is the basic principle diagram of the heavy-load robotic arm potential energy recovery system.

[0018] In the figure: 1- hydraulic pump; 2- power element; 3- three-position four-way solenoid valve; 4- three-chamber hydraulic cylinder; 5- first proportional valve; 6- accumulator; 7- second proportional valve; 8- third proportional valve; 9- overflow valve; 10- oil tank; 11- first pressure sensor; 12- second pressure sensor; 13- rangefinder; 14- camera; 15- one-way valve; 16- controller; 17- operating handle. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] The purpose of the present invention is to provide a heavy-duty robotic arm potential energy recovery system and control method to solve the problems existing in the above-mentioned prior art, which can automatically switch working states, reduce the misjudgment rate, improve the controllability of the whole machine, and improve the potential energy recovery rate.

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1

[0023] This embodiment provides a heavy-duty robotic arm potential energy recovery system. Figure 1As shown, it includes an oil tank 10, a hydraulic pump 1, a power element 2, a three-position four-way solenoid valve 3, a three-chamber hydraulic cylinder 4, a first pressure sensor 11, a second pressure sensor 12, a first proportional valve 5, a second proportional valve 7, a third proportional valve 8, an accumulator 6, a rangefinder 13 and a controller 16; the power element 2 is transmission-connected to the hydraulic pump 1, the oil inlet of the hydraulic pump 1 is connected and communicated with the oil tank 10, the oil outlet of the hydraulic pump 1 is connected and communicated with the oil inlet of the three-position four-way solenoid valve 3, the first oil outlet of the three-position four-way solenoid valve 3 is connected and communicated with the rod cavity of the three-chamber hydraulic cylinder 4, and the first pressure sensor 11 is provided on the pipeline connecting the first oil outlet of the three-position four-way solenoid valve 3 and the rod cavity of the three-chamber hydraulic cylinder 4, and the second oil outlet of the three-position four-way solenoid valve 3 is connected to the rodless cavity of the three-chamber hydraulic cylinder 4 The oil inlet of the first proportional valve 5 and the oil inlet of the second proportional valve 7 are both connected and communicated with the energy storage chamber of the three-chamber hydraulic cylinder 4, the oil outlet of the first proportional valve 5 is connected and communicated with the accumulator 6, and a second pressure sensor 12 is provided on the pipeline connecting the oil outlet of the first proportional valve 5 and the accumulator 6, the oil outlet of the second proportional valve 7 is connected and communicated with the oil tank 10, the accumulator 6 is connected and communicated with the oil outlet of the third proportional valve 8, the oil inlet of the third proportional valve 8 is connected and communicated with the hydraulic pump 1, and a rangefinder 13 is fixedly installed on the bucket, the rangefinder 13 is used to detect the distance between the bucket and the ground, the first pressure sensor 11, the second pressure sensor 12, the first proportional valve 5, the second proportional valve 7, the third proportional valve 8 and the rangefinder 13 are all connected with the controller 16 signal. The pressure of the rod chamber of the three-chamber hydraulic cylinder 4 is collected by the first pressure sensor 11 as the first signal for multi-mode control judgment. The rangefinder 13 is set to collect the distance from the bucket to the excavation surface in real time as the second signal for multi-mode control judgment. The pressure signal and the distance signal are both transmitted to the controller 16. The controller 16 analyzes and judges the two signals, thereby realizing automatic identification of the excavator working condition. Then the controller 16 completes the automatic switching of the multi-mode control system by controlling the opening of the first proportional valve 5 and the second proportional valve 7. Only when the two signals meet the preset conditions at the same time can it be determined that the excavator has entered the special working mode of supporting the ground. When the controller After the controller 16 determines that the signal meets the preset conditions for boom lifting, the controller 16 switches to the original energy recovery mode. The two signals ensure that the controller 16 can make a correct judgment to avoid misjudgment of the controller 16 due to a sudden change of a certain signal. The controller 16 can accurately identify the working state of the excavator and automatically control the switching of working modes to ensure the timeliness and smoothness of the switching; in the boom lifting stage, the signal is collected by the second pressure sensor 12 and transmitted to the controller 16, and a pressure closed-loop control strategy is set. The controller 16 outputs a signal to control the opening of the third proportional valve 8 to realize a pressure closed loop, thereby ensuring the pressure stability of the entire system loop.Preferably, the controller 16 is connected to the control handle signal, and the operator can actively input the signal to the controller 16 through the control handle to complete the heavy-load impact action. The controller 16 analyzes the distance signal of the rangefinder 13. When the bucket descends to the set position, the controller 16 switches to a special working mode to unload the three-chamber hydraulic cylinder 4, and the boom descends rapidly to obtain impact kinetic energy.

[0024] It is further preferred in the implementation manner of this embodiment that a flow direction check valve 15 is provided on the pipeline connecting the oil outlet of the third proportional valve 8 and the accumulator 6 .

[0025] In the embodiment of this invention, the heavy-duty manipulator arm potential energy recovery system further includes a camera 14, which is fixedly mounted on the bucket and signal-connected to a controller 16. The camera 14 is configured to capture real-time images of the bucket's operation. The video signal from the camera 14 is transmitted to the controller 16, which uses machine vision to analyze the bucket's operation in real time. This signal serves as a third signal for multi-mode control determination. When all three signals simultaneously meet preset conditions, the excavator is determined to have entered a special operating mode, further enhancing the accuracy of the operating status determination.

[0026] In the embodiment of this invention, the heavy-duty manipulator potential energy recovery system further includes a relief valve 9. The accumulator 6 is connected to and communicates with the oil tank 10, and the relief valve 9 is provided on the pipeline connecting the accumulator 6 and the oil tank 10. The relief valve 9 serves to protect the heavy-duty manipulator potential energy recovery system.

[0027] Example 2

[0028] This embodiment provides a control method for the heavy-load robotic arm potential energy recovery system using the embodiment 1, including a robotic arm descending condition and a robotic arm ascending condition;

[0029] Robotic arm descending working condition:

[0030] The first pressure sensor 11 transmits the pressure information of the rod chamber of the monitored three-chamber hydraulic cylinder 4 to the controller 16 in real time, and the controller 16 analyzes the pressure of the rod chamber of the three-chamber hydraulic cylinder 4. The rangefinder 13 transmits the measured distance from the bucket to the working surface to the controller 16 in real time, and the controller 16 analyzes whether the bucket is in contact with the working surface; based on the pressure information and distance information received by the controller 16, it is jointly determined whether the working condition requiring the boom to be lowered is required; when the pressure signal and the distance signal simultaneously meet the lowering working condition, the controller 16 obtains the working condition information that the robotic arm is in the robotic arm lowering condition; the controller 16 controls the closing of the first proportional valve 5, cutting off the passage between the energy storage chamber of the three-chamber hydraulic cylinder 4 and the accumulator 6, and at the same time opens the second proportional valve 7, connecting the passage between the energy storage chamber of the three-chamber hydraulic cylinder 4 and the oil tank 10, and unloading the energy storage chamber of the three-chamber hydraulic cylinder 4, so that the robotic arm can be lowered smoothly;

[0031] Working condition of the robotic arm descending and then ascending:

[0032] After the excavator is in the arm-lowering state, the controller 16 continues to collect and analyze pressure and distance signals. When the controller 16 determines that the preset conditions for the arm's ascent are met, the controller 16 opens the first proportional valve 5, connecting the energy storage chamber of the three-chamber hydraulic cylinder 4 with the accumulator 6. At the same time, it closes the second proportional valve 7, cutting off the passage between the energy storage chamber of the three-chamber hydraulic cylinder 4 and the oil tank 10. The hydraulic oil in the accumulator 6 enters the energy storage chamber of the three-chamber hydraulic cylinder 4 through the first proportional valve 5, achieving the ascent and merging of the arm. When the pressure monitored by the second pressure sensor 12 received by the controller 16 is insufficient, the controller 16 controls the opening of the third proportional valve 8 to implement pressure closed-loop control, ensuring that the excavator can maintain normal operation in energy recovery mode. Through pressure closed-loop control, while adding a switching control system to the excavator, it also supports all functions of the original system, ensuring the integrity of the system and improving the controllability of the entire machine. This allows the efficient and simple boom potential energy recovery method to not only remain in the laboratory stage but also provide market opportunities.

[0033] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A heavy-duty robotic arm potential energy recovery system, characterized by: and a control panel containing the control panel, wherein the control panel has two control panels, one is for controlling the oil pressure in the oil pump and the other is for controlling the oil inlet of the oil pump, the other is for controlling the oil pressure in the oil pump, and the other is for controlling the oil pressure in the oil pump. The second pressure sensor is provided on the pipeline connecting the oil outlet of the proportional valve and the accumulator, the oil outlet of the second proportional valve is connected to and communicated with the oil tank, the oil inlet of the third proportional valve is connected to and communicated with the hydraulic pump, the accumulator is connected to and communicated with the oil outlet of the third proportional valve, the rangefinder is fixedly mounted on the bucket, and the rangefinder is used to detect the distance between the bucket and the ground, the first pressure sensor, the second pressure sensor, the first proportional valve, the second proportional valve, the third proportional valve and the rangefinder are all signal-connected to the controller, the working status of the excavator can be measured in real time through the first pressure sensor and the rangefinder, and the collected signal is transmitted to the controller, which analyzes and judges, thereby realizing automatic identification of the excavator working condition, and the controller completes automatic switching of the multi-mode control system by controlling the opening of the first proportional valve and the second proportional valve, effectively avoiding misjudgment caused by signal mutation.

2. The heavy-duty robotic arm potential energy recovery system according to claim 1, characterized in that: A flow direction check valve is provided on the pipeline connecting the oil outlet of the third proportional valve and the accumulator.

3. The heavy-duty robotic arm potential energy recovery system according to claim 1, characterized in that: It also includes a camera, which is fixedly installed on the bucket and is connected to the controller signal.

4. The heavy-duty robotic arm potential energy recovery system according to claim 1, characterized in that: It also includes a relief valve. The accumulator is connected and communicated with the oil tank, and the relief valve is provided on the pipeline communicating between the accumulator and the oil tank.

5. A control method using the heavy-load manipulator potential energy recovery system according to any one of claims 1 to 4, characterized in that: Including the robot arm descending working condition and the robot arm ascending working condition; Robotic arm descending working condition: The controller determines whether the boom is in a working condition requiring a lowering of the boom based on the pressure information of the rod chamber of the three-chamber hydraulic cylinder monitored by the first pressure sensor and the distance information from the bucket to the excavation surface collected by the rangefinder. The controller determines that the boom is in a lowering working condition only when both the pressure signal and the distance signal satisfy the lowering working condition. The controller controls the closing of the first proportional valve to cut off the passage between the energy storage chamber of the three-chamber hydraulic cylinder and the accumulator, and simultaneously opens the second proportional valve to connect the passage between the energy storage chamber of the three-chamber hydraulic cylinder and the oil tank, thereby unloading the energy storage chamber of the three-chamber hydraulic cylinder, thereby allowing the robotic arm to descend smoothly; Working condition of the robotic arm descending and then ascending: After the excavator is in the working condition of lowering the mechanical arm, the controller continues to collect and analyze the pressure signal and the distance signal. When the controller determines that the preset conditions for the raising of the mechanical arm are met, the controller opens the first proportional valve to connect the energy storage chamber of the three-chamber hydraulic cylinder with the passage of the accumulator, and at the same time closes the second proportional valve to cut off the passage between the energy storage chamber of the three-chamber hydraulic cylinder and the oil tank. The hydraulic oil in the accumulator enters the energy storage chamber of the three-chamber hydraulic cylinder through the first proportional valve to realize the raising and merging of the mechanical arm; when the pressure monitored by the second pressure sensor received by the controller is insufficient, the controller controls the opening of the third proportional valve to realize pressure closed-loop control to ensure that the excavator can maintain normal operation in the energy recovery mode.

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