A hydraulic control system for a foot-type hydraulic robot with energy recovery

Abstract

The present invention discloses a hydraulic control system for a foot-type hydraulic robot capable of energy recovery. The system is configured with a hydraulic pump capable of bidirectional rotation and reversible oil inlet and outlet directions, and adopts an electromagnetic switch valve as an accumulator and a drain valve for the oil circuit of the hydraulic pump inlet, so as to realize timely energy recovery; an electromagnetic switch valve is adopted as a switching valve for connecting the oil return chamber of the leg-foot joint cylinder with the low-pressure circuit of the oil tank or the oil circuit connected to the accumulator, so as to realize the recovery of overload energy of the leg-foot joint cylinder; an independent hydraulic system is configured for each leg-foot, so that the flow and pressure of the hydraulic system between each leg-foot do not interfere with each other, so as to realize overload energy recovery under complex working conditions and gaits. The present invention can realize precise control of overload energy recovery and reuse of the foot-type hydraulic robot, effectively reduce the energy consumption of the hydraulic system, and further improve its working endurance.

Description

Technical Field

[0001] The invention relates to a hydraulic control system, in particular to a hydraulic control system of a foot-type hydraulic robot capable of energy recovery. Background Art

[0002] In recent years, legged hydraulic robots have been valued by many domestic and foreign universities, research institutes, and military science and technology departments for their high power-to-weight ratio, flexible movement, and strong environmental adaptability. In the future, these legged hydraulic robots are expected to play an important role in mountain transportation, rescue and geological survey. These application areas require long-term continuous work in complex field environments, which not only requires high environmental adaptability, rapid response, system stability, and motion accuracy of legged hydraulic robots, but also requires high working endurance.

[0003] The traditional legged hydraulic robot energy recovery hydraulic system is configured as a single hydraulic system to supply oil to multiple legs and multiple joints actuators at the same time, and the accumulator is installed at the pump outlet. When the flow required by the system decreases, the high-pressure oil enters the accumulator. When the flow required by the system increases, the oil in the accumulator supplies the system, which achieves energy recovery to a certain extent. However, this traditional hydraulic control system cannot control the energy storage and release, and cannot achieve overload energy recovery for each leg in different motion conditions, which seriously affects the energy utilization efficiency of the legged hydraulic robot. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the present invention proposes a hydraulic control system for a foot-type hydraulic robot which can further reduce energy consumption, improve working endurance, and has a single-leg overload energy recovery function. The foot-type robot can configure this hydraulic control system according to the present invention and in combination with its actual leg and foot structure and number of legs and feet to achieve efficient energy recovery.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] A hydraulic control system for a foot-type hydraulic robot with energy recovery, comprising a servo motor 1, a hydraulic pump 2, a relief valve 3, an accumulator 4, a common joint drive control unit group 5, an energy-recoverable joint oil cylinder control valve 6, an energy-recoverable joint oil cylinder 7, an energy storage oil circuit switching valve 8, an energy storage oil circuit check valve 9, an accumulator drain valve 10, an oil return check valve 11, and an oil tank 12; a branch at the oil outlet p2 of the hydraulic pump 2 is connected to the oil tank 12 after passing through the relief valve 3 to form an overflow circuit of the system, and the other branch is connected to the common joint drive control unit group 5, the energy-recoverable joint oil cylinder control valve 6, the energy-recoverable joint oil cylinder 7, the energy storage oil circuit switching valve 8, the energy storage oil circuit check valve 9, the accumulator drain valve 10, the oil return check valve 11, and the oil tank 12; a branch at the oil outlet p2 of the hydraulic pump 2 is connected to the oil tank 12 after passing through the relief valve 3 to form an overflow circuit of the system, and the other branch is connected to the common joint drive control unit group 5, the energy-recoverable joint oil cylinder control valve 6, the energy recovery joint oil cylinder 7, the energy storage oil circuit switching valve 8, the energy storage oil circuit check valve 9, the accumulator drain valve 10, the oil return check valve 11, and the oil tank 12; a branch at the oil outlet p2 of the hydraulic pump 2 is connected to the oil tank 12 after passing through the relief valve 3 to form an overflow circuit of the system, and the other branch is connected to the common joint drive control unit group 5, the energy recovery joint oil cylinder control valve 6, the energy recovery joint oil cylinder 7, the energy storage oil circuit switching valve 8, the energy storage oil circuit check valve 9, the accumulator drain valve 10, the oil return check valve 11, and the oil tank 12 The main oil inlet a5 of the motion control unit group 5 and the oil inlet p6 of the overload energy recovery joint cylinder control valve; the main oil return port b5 of the ordinary joint drive control unit group 5 is connected to the oil tank 12; one branch of the oil return port b6 of the energy recovery joint cylinder control valve 6 is connected to the oil tank 12 through the energy storage oil circuit switching valve 8, and the other branch is connected to the accumulator 4 after passing through the energy storage oil circuit check valve 9; one branch at the oil inlet t2 of the hydraulic pump 2 is connected to the oil tank 12 after passing through the oil return check valve 11, and the other branch is connected to the accumulator 4 through the accumulator drain valve 10.

[0007] Furthermore, the overload energy recovery joint cylinder 7 is arranged on the joint mechanism of the single leg of the foot-type hydraulic robot that generates the most overload energy, and its oil inlet and outlet are connected to the working oil port of the overload energy recovery joint cylinder control valve 6; the overload energy recovery joint cylinder control valve 6 adopts a three-position four-way proportional reversing valve, and the valve core and the opening degree are controlled by electrical signals, thereby controlling the movement direction and speed of the overload energy recovery joint cylinder 7; the hydraulic pump 2 adopts a quantitative pump that can rotate in both directions and has reversible oil inlet and outlet directions. The system flow can be controlled by adjusting the speed of the servo motor 1, and the system flow can be supplied on demand, which greatly reduces the system energy consumption in terms of energy supply; the energy storage oil circuit switching valve 7 and the accumulator drain valve 10 both adopt electromagnetic switch valves.

[0008] Furthermore, the common joint drive control unit group 5 contains multiple common joint drive valve-controlled cylinder units, and the number of units contained therein is determined by the number of joints of a single leg of the robot; the common joint drive unit is composed of a common joint drive cylinder and a corresponding common joint drive cylinder control valve; the common joint drive cylinder is arranged at the joint of the single leg where not much energy can be recovered, and the common joint drive cylinder control valve adopts a three-position four-way proportional reversing valve, whose working oil port is connected to the corresponding common joint drive cylinder inlet and outlet oil ports, and the oil inlets are connected to the total oil inlet a5 of the unit group after being connected to each other, and the oil outlets are connected to the total oil outlet b5 of the unit group after being connected to each other and then connected to the oil tank 12.

[0009] Compared with the prior art, the present invention has the following beneficial effects:

[0010] 1. The present invention uses the energy storage oil circuit for energy recovery in conjunction with the electromagnetic switch valve, which can control the energy recovery process, achieve timely recovery and timely utilization, effectively reduce energy consumption, and further improve the energy recovery efficiency and working endurance of the foot-type hydraulic robot.

[0011] 2. The present invention adopts a distributed drive solution in which each leg of the anteropod hydraulic robot is equipped with an independent hydraulic system. Different energy recovery control methods can be adopted according to the working conditions of each leg, and can achieve intelligent utilization of load energy recovery.

[0012] 3. The present invention can be realized by configuring lightweight and compact hydraulic components, which can be quickly "transplanted" into the original hydraulic system without basically changing the original system layout, greatly saving the system redesign and layout costs, and is suitable for highly integrated electromechanical and hydraulic equipment such as foot-type hydraulic robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of a hydraulic control system of a foot-type hydraulic robot with energy recovery according to the present invention;

[0014] Figure 2 It is a schematic diagram of a common joint drive control unit;

[0015] Figure 3 is a schematic diagram of the system of the present invention under impedance extension working condition;

[0016] Figure 4 is a schematic diagram of the system of the present invention under the impedance retraction condition;

[0017] Figure 5 is a schematic diagram of the system of the present invention under the overrunning extension working condition;

[0018] Figure 6 is a schematic diagram of the system of the present invention under the overrunning and retracting working condition;

[0019] Figure 7 It is a schematic diagram of a distributed hydraulic control system of a bipedal hydraulic robot with energy recovery, which is an embodiment of the present invention; DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings. Wherever possible, corresponding or similar reference numerals used in these drawings represent identical or corresponding parts.

[0021] Now refer to Figure 1 and Figure 2, a hydraulic control system for a foot-type hydraulic robot with energy recovery, the system can input gait tracking control signals to each joint cylinder control valve to control the joint cylinders of the legs and feet to work in four-quadrant conditions; when under impedance load, the load force and speed are in opposite directions, and the hydraulic cylinder can extend and retract; when overrunning load, the load force and speed are the same, and the hydraulic cylinder can extend and retract; by changing the opening and closing states of each switch valve in the system schematic diagram, the overrunning load energy generated by the same speed direction and load force direction on the energy recovery joint cylinder 7 can be recovered and utilized; it should be noted that the number of ordinary joint drive control units of the ordinary joint drive control unit group 5 is determined by the number of single leg joints of the foot-type hydraulic robot; Figure 1 Taking a single-leg two-joint foot hydraulic robot as an example, if the number of single-leg joints increases, the number of ordinary joint drive control units will increase accordingly.

[0022] Now refer to Figure 3 , the energy recovery joint cylinder control valve 6 inputs the action control signal, when the energy recovery joint cylinder 7 works under the impedance extension condition: the rodless chamber of the energy recovery joint cylinder 7 is connected to the high-pressure oil circuit; the energy storage oil circuit switching valve 8 is energized, and the rod chamber of the energy recovery joint cylinder 7 is connected to the oil tank 12; the accumulator drain valve 10 is energized, connecting the oil circuit between the accumulator 4 and the hydraulic pump oil inlet t2, and the return oil check valve 11 will prevent the high-pressure fluid from entering the oil tank, so the high-pressure fluid in the accumulator 4 can only enter the hydraulic pump 2, assisting the servo motor to do work and realizing energy utilization.

[0023] Now refer to Figure 4 The energy recovery joint cylinder control valve 6 inputs an action control signal. When the energy recovery joint cylinder 7 works under the impedance retraction condition, the rod chamber of the energy recovery joint cylinder 7 is connected to the high-pressure oil circuit; the energy storage oil circuit switching valve 8 is energized, and the rodless chamber of the overload energy recovery joint cylinder 7 is connected to the oil tank 12; the accumulator drain valve 10 is energized, connecting the oil circuit between the accumulator 4 and the hydraulic pump oil inlet t2, and the return oil check valve 11 will prevent the high-pressure fluid from entering the oil tank, so the high-pressure fluid in the accumulator 4 can only enter the hydraulic pump 2, assisting the servo motor to do work and realizing energy utilization.

[0024] Now refer to Figure 5 The overload energy recovery joint cylinder control valve 6 inputs an action control signal. When the energy recovery joint cylinder 7 works in the overextending condition, the rodless chamber of the energy recovery joint cylinder 7 is connected to the high-pressure oil circuit; the electromagnet of the energy storage oil circuit switching valve 8 loses power, so that the rod chamber of the energy recovery joint cylinder 7 is connected to the accumulator 4; the electromagnet of the accumulator drain valve 10 loses power, closing the oil circuit between the accumulator 4 and the hydraulic pump oil inlet t2, and the oil in the rod chamber of the energy recovery joint cylinder 7 is pressurized into a high-pressure fluid under the action of the overload energy, opening the energy storage oil circuit one-way valve 9 and entering the accumulator 4 to realize energy recovery.

[0025] Now refer to Figure 6 The energy recovery joint cylinder control valve 6 inputs an action control signal. When the energy recovery joint cylinder 7 works in the overrunning retraction condition, the rod chamber of the energy recovery joint cylinder 7 is connected to the high-pressure oil circuit; the electromagnet of the energy storage oil circuit switching valve 8 loses power, so that the rod chamber of the energy recovery joint cylinder 7 is connected to the accumulator 4; the electromagnet of the accumulator drain valve 10 loses power, closing the oil circuit between the accumulator 4 and the hydraulic pump oil inlet t2, and the oil in the rod chamber of the energy recovery joint cylinder 7 is pressurized into a high-pressure fluid under the action of the overrunning load energy, opening the energy storage oil circuit one-way valve 9 and entering the accumulator 4 to realize energy recovery.

[0026] Now refer to Figure 7 In this embodiment, a schematic diagram of a distributed hydraulic control system of a bipedal hydraulic robot with energy recovery is shown. In the embodiment shown, the hydraulic system 300 is composed of two sets of the right leg hydraulic system 100 and the left leg hydraulic system 200 of the present invention in a distributed arrangement.

[0027] In this embodiment, the right leg hydraulic system 100 and the left leg hydraulic system 200 are independent in the hydraulic system, and the oil flow and pressure do not interfere with each other during operation; the joint cylinders are interconnected in control and cooperate with each other to complete various actions of the bipedal hydraulic robot.

[0028] In this embodiment, the bipedal hydraulic robot is provided with two joints on each leg, and the overload energy is mainly distributed on the thigh joint cylinder, so the overload energy recovery joint cylinder 107, 207 should be arranged on the thigh, and the ordinary joint drive control unit groups 105, 205 each have only one ordinary joint drive unit, and are arranged on the calf joint.

[0029] In this embodiment, the working principle and control method are as follows: the system is started, and the quantitative pumps 102, 202 of each leg system provide appropriate pressure and flow for each leg system under the drive of its servo motor 101, 102, and the common joint cylinder control valves 1051, 2051 and the overload energy recovery joint cylinder control valves 106, 206 are input with gait tracking control signals by the controller, and the overload energy recovery joint cylinders 107, 207 of the biped hydraulic robot work in four-quadrant conditions; by monitoring the motion conditions of the overload energy recovery joint cylinders 107, 207, and according to the motion conditions, the corresponding Figures 3 to 6 By changing the opening and closing states of each switch valve in the system in the manner shown, the overload energy generated by the energy recovery joint cylinders 107 and 207 can be recovered and utilized.

[0030] It should be understood that the parts not elaborated in detail in this specification belong to the prior art. The above embodiments are only descriptions of the preferred implementation methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made by engineers and technicians in this field to the technical solution of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A hydraulic control system for a foot-type hydraulic robot with energy recovery, comprising a servo motor, a hydraulic pump, a relief valve, an accumulator, a common joint drive control unit group, an energy-recoverable joint cylinder control valve, an energy-recoverable joint cylinder, an energy storage oil circuit switching valve, an energy storage oil circuit check valve, an accumulator drain valve, an oil return check valve, and an oil tank. A branch at the oil outlet of the hydraulic pump is connected to the oil tank after passing through the relief valve to form an overflow circuit of the system, and the other branch is respectively connected to the total oil inlet of the common joint drive control unit group and the oil inlet of the overload energy recovery joint cylinder control valve; the common close The main oil return port of the joint drive control unit group is connected to the oil tank; one branch of the oil return port of the energy recovery joint cylinder control valve is connected to the oil tank through the energy storage oil circuit switching valve, and the other branch is connected to the accumulator after passing through the energy storage oil circuit check valve; one branch at the oil inlet of the hydraulic pump is connected to the oil tank after passing through the return oil check valve, and the other branch is connected to the accumulator through the accumulator drain valve. Further, the overload energy recovery joint cylinder is arranged on the joint mechanism of the single leg of the foot-type hydraulic robot that generates the most overload energy, and its oil inlet and outlet are connected to the working oil port of the overload energy recovery joint cylinder control valve; the The overload energy recovery joint oil cylinder control valve adopts a three-position four-way proportional reversing valve, and the three-position four-way proportional reversing valve core and opening degree are controlled by electrical signals, so as to control the movement direction and speed of the overload energy recovery joint oil cylinder; the hydraulic pump adopts a two-way rotating, reversible quantitative pump, and the system flow can be controlled by adjusting the speed of the servo motor, which can realize the system flow supply on demand and greatly reduce the system energy consumption in terms of energy supply; the energy storage oil circuit switching valve and the accumulator discharge valve both adopt electromagnetic switch valves. Furthermore, the ordinary joint drive control unit group contains A plurality of common joint drive valve-controlled cylinder units, the number of which is determined by the number of joints of a single leg of the robot; the common joint drive unit is composed of a common joint drive cylinder and a corresponding common joint drive cylinder control valve; the common joint drive cylinder is arranged at a joint on a single leg where not much energy can be recovered, the common joint drive cylinder control valve adopts a three-position four-way proportional reversing valve, the working oil port of which is connected to the corresponding common joint drive cylinder inlet and outlet, the oil inlets of which are connected to each other and connected to the total oil inlet of the unit group, the oil outlets of which are connected to each other and connected to the total oil outlet of the unit group and then connected to the oil tank.

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