An on-board hydraulic station suitable for a quadruped robot

Abstract

The application discloses an on-board hydraulic station suitable for a quadruped robot and belongs to the technical field of bionic robots. The on-board hydraulic station comprises a main oil supply device and an auxiliary oil supply device which are used for being mounted on the quadruped robot and are fixedly connected. The main oil supply device is used for being communicated with a low-pressure oil return path of the quadruped robot and a high-pressure oil supply path of the quadruped robot through a hydraulic pump. The low-pressure oil return path of the quadruped robot and the high-pressure oil supply path of the quadruped robot are respectively used for supplying oil and returning oil to a rodless cavity of a hip pitching joint hydraulic actuator, a hip lateral swing joint hydraulic actuator and a knee pitching joint actuator of the quadruped robot through a three-position four-way valve I, a three-position four-way valve II and a three-position three-way valve. The auxiliary oil supply device is provided with a high-pressure oil inlet and outlet joint which is used for supplying oil and returning oil to a rod cavity of the knee pitching joint actuator. The on-board hydraulic station adopts a double-oil-tank design, has good integration and high energy utilization rate, and effectively solves the problem of low motion energy efficiency of a hydraulic quadruped robot.

Description

Technical Field

[0001] This invention relates to the field of biomimetic robot technology, and in particular to an onboard hydraulic station suitable for quadruped robots. Background Technology

[0002] Terrestrial animals employ numerous methods of locomotion to adapt to different environments, such as legged locomotion and peristaltic locomotion. However, hundreds of millions of years of natural evolution have shown that legged locomotion remains the most efficient and adaptable mode of movement, considering factors such as terrain adaptability and overall locomotion efficiency. Therefore, exploring the locomotion potential of robots from a biomimetic perspective and developing legged robots with strong flexibility and terrain adaptability for unstructured outdoor environments, especially hydraulic quadruped robots suitable for heavy-duty long-distance load-bearing, has significant practical implications and broad application prospects.

[0003] The main factor limiting the widespread adoption of hydraulic quadruped robots is energy consumption. This energy consumption issue stems primarily from two factors: First, the inherent properties of hydraulic transmission systems mean that, as a form of mediated transmission, high-pressure fluid in a closed pipe will generate energy loss without any energy consumption. This directly determines that hydraulic transmission has lower energy conversion efficiency compared to electric drive systems. Second, from the perspective of drive system construction, most current hydraulic quadruped robot drive system construction methods prioritize single-objective precision and high dynamic response, striving to ensure that each joint actuator maintains ideal displacement and force output response at all times through stable high-pressure oil supply before the valve. However, this neglects the actual motion requirements within different phases of the robot's movement. Specifically, for traditional two-stage, three-DOF quadruped robot limb structures, while each joint actuator currently uses stable high-pressure oil supply before the valve, only the actuators in the support phase bear a large load, while the actuators in the swing phase bear a smaller load. Therefore, using traditional drive methods for the actuators in the swing phase undoubtedly leads to energy waste. Thirdly, from the perspective of quadruped robot design, as a type of high-dynamic floating coordinate heavy-duty mobile carrier, the power-to-weight ratio has always been one of the important indicators for evaluating hydraulic quadruped robots. However, designing a centralized airborne station with high integration, low impact, and outstanding energy efficiency within limited installation space is a significant engineering challenge. This indirectly makes it difficult to adopt most of the hydraulic transmission system construction schemes that are already maturely applied in engineering. Therefore, how to design an airborne high-efficiency hydraulic station with good integration and dynamism, high energy conversion rate, and good application value to meet the application needs of quadruped robots is a common problem currently faced in the research field of hydraulically driven quadruped robots, and it has high theoretical research significance and practical application value. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems and provide an airborne hydraulic station suitable for quadruped robots. This airborne hydraulic station adopts a dual-tank design, which has good integration and high energy utilization. It not only ensures the reliability of the position and force servo of each hydraulic cylinder during the support phase, but also reduces the piston back pressure for the motion function of the hydraulic cylinder retraction phase of the knee joint pitch actuator during the swing phase, effectively solving the problem of low motion energy efficiency of current hydraulic quadruped robots.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention discloses an onboard hydraulic station suitable for quadruped robots, including a main oil supply device and an auxiliary oil supply device for installation on the quadruped robot. The main oil supply device and the auxiliary oil supply device are fixedly connected. The main oil supply device is used to connect to the low-pressure return oil circuit of the quadruped robot and to the high-pressure oil supply circuit of the quadruped robot through a hydraulic pump. The low-pressure return oil circuit and the high-pressure oil supply circuit of the quadruped robot supply oil and return oil to the rodless chambers of the hip pitch joint hydraulic actuator, the hip lateral swing joint hydraulic actuator, and the knee pitch joint actuator of the quadruped robot through a three-position four-way valve I, a three-position four-way valve II, and a three-position three-way valve, respectively. The auxiliary oil supply device is provided with a high-pressure oil inlet and outlet connector for supplying and returning oil to the rod chamber of the knee pitch joint actuator.

[0006] Preferably, the main oil supply device is equipped with a low-pressure oil outlet connector, a high-pressure oil return connector, and a high-pressure oil supply connector. The inlet end of the low-pressure oil outlet connector is connected to the main oil supply device. The outlet end of the low-pressure oil outlet connector is connected to the low-pressure oil return circuit of the quadruped robot and the oil suction port of the hydraulic pump via a tee. The oil supply port of the hydraulic pump is connected to the inlet end of the high-pressure oil return connector. The outlet end of the high-pressure oil return connector is connected to the inlet end of the high-pressure oil supply connector. The outlet end of the high-pressure oil inlet connector is used to connect to the high-pressure oil supply circuit of the quadruped robot.

[0007] Preferably, the auxiliary oil supply device includes an air chamber with an auxiliary air chamber cavity, an auxiliary sealed oil tank with an auxiliary oil chamber cavity, and a volume-adjusting hydraulic cylinder disposed on the air chamber cavity; the auxiliary air chamber cavity is sealed to the auxiliary air chamber cavity through an auxiliary piston sealing assembly, the auxiliary piston sealing assembly including an auxiliary sealing limiting ring fixed to one end of the main oil chamber cavity near the main air chamber cavity, and an auxiliary piston bushing sealed within the auxiliary sealing limiting ring, the end of the auxiliary piston bushing being fixed with a part located in the main oil chamber cavity. The auxiliary fluid level adjusting piston is located inside the cavity. The auxiliary sealed oil tank is equipped with an auxiliary one-way air charging valve group that communicates with the auxiliary air chamber. The high-pressure oil inlet / outlet connector is connected to the auxiliary sealed oil tank. The output shaft of the volume adjusting hydraulic cylinder is equipped with a volume adjusting piston that extends into the auxiliary air chamber. The oil inlet of the volume adjusting hydraulic cylinder is connected to the high-pressure oil supply connector, and the oil outlet of the volume adjusting hydraulic cylinder is connected to the low-pressure return oil circuit of the quadruped robot. An auxiliary fluid level sensor is installed inside the auxiliary oil chamber.

[0008] Preferably, the volume-adjusting hydraulic cylinder includes a hydraulic cylinder body and an electro-hydraulic servo valve. The hydraulic cylinder body is provided with a pressure regulating piston that can divide its interior into a first injection chamber and a second injection chamber. The output shaft of the volume-adjusting hydraulic cylinder is fixed on the pressure regulating piston. The electro-hydraulic servo valve communicates with the first injection chamber and the second injection chamber. The hydraulic cylinder body is provided with an adjusting oil inlet connector and an adjusting oil outlet connector that communicate with the electro-hydraulic servo valve. The adjusting oil inlet connector is connected to the high-pressure oil supply connector, and the adjusting oil outlet connector is connected to the low-pressure return oil circuit of the quadruped robot.

[0009] Preferably, the auxiliary liquid level detector includes an auxiliary sensor bushing and an auxiliary sensor friction shaft. The auxiliary sensor bushing is disposed inside the auxiliary piston bushing and fixedly connected to the auxiliary liquid level adjusting piston. The auxiliary sensor friction shaft is fixed inside the auxiliary oil chamber. The auxiliary liquid level adjusting piston is provided with an auxiliary sealing guide hole for the auxiliary sensor friction shaft to extend into the auxiliary sensor bushing. The auxiliary sensor bushing is slidably connected to the auxiliary sensor friction shaft.

[0010] Preferably, the main oil supply device includes an accumulator and a main sealed oil tank. The accumulator contains a spherical air bladder for forming the main gas chamber. The main sealed oil tank contains a main oil chamber, which is sealed to the main gas chamber via a main piston sealing assembly. The main piston sealing assembly includes a main sealing limiting ring fixed to one end of the main oil chamber near the main gas chamber, and a main piston bushing sealed within the main sealing limiting ring. A main liquid level adjusting piston located inside the main oil chamber is fixed to the end of the main piston bushing. The main sealed oil tank is equipped with a main one-way air charging valve assembly communicating with the main gas chamber, and a low-pressure oil outlet connector communicating with the main oil chamber. A main liquid level sensor is provided inside the main oil chamber.

[0011] Preferably, the main liquid level detector includes a main sensor bushing and a main sensor friction shaft. The main sensor bushing is disposed inside the main piston bushing and is fixedly connected to the main liquid level adjusting piston. The main sensor friction shaft is fixed inside the main oil chamber. The main liquid level adjusting piston is provided with a main sealing guide hole for the main sensor friction shaft to extend into the main sensor bushing. The main sensor bushing is slidably connected to the main sensor friction shaft.

[0012] Preferably, the main sealed oil tank is provided with a low-pressure fast charging connector communicating with the main oil chamber, and the auxiliary sealed oil tank is provided with a high-pressure oil filling port communicating with the auxiliary oil chamber. The high-pressure oil filling port is connected to the high-pressure oil supply connector through an oil filling valve block assembly. A low-pressure oil filter, a low-pressure oil circuit pressure limiting valve, and a low-pressure oil circuit temperature sensor are connected in series between the low-pressure fast charging connector and the main oil chamber. A high-pressure oil circuit pressure limiting valve and a high-pressure oil filter are provided in series between the high-pressure oil return connector and the high-pressure oil supply connector.

[0013] Preferably, the oil filling valve block assembly includes an oil passage block and a two-position two-way reversing valve. The oil passage block is provided with a first pipeline, a second pipeline, a third pipeline, a fourth pipeline, and a fifth pipeline. The high-pressure oil supply connector is disposed on the oil passage block and is connected to the outlet end of the first pipeline. The inlet end of the first pipeline is connected to the high-pressure return oil connector, and the outlet end of the first pipeline is connected to the high-pressure oil supply connector. The inlet end of the second pipeline is connected to the outlet end of the first pipeline, and the outlet end of the second pipeline is connected to the inlet end of the third pipeline. The outlet end of the third pipeline is connected to the inlet end of the two-position two-way reversing valve, and the outlet end of the two-position two-way reversing valve is connected to the inlet end of the fourth pipeline. The outlet end of the fourth pipeline is connected to the inlet end of the fifth pipeline, and the outlet end of the fifth pipeline is connected to the high-pressure oil filling port.

[0014] Preferably, an electromagnetic unloading valve is connected between the oil supply circuit and the oil return circuit of the main oil supply device.

[0015] The present invention achieves the following technical effects compared to the prior art:

[0016] 1. The airborne hydraulic station in this invention adopts a dual oil supply device design. The main oil supply device is connected in series with an external hydraulic pump to form a conventional hydraulic servo oil circuit, which supplies oil to the rodless chambers of the robot's hip pitch joint hydraulic actuator, hip lateral swing joint hydraulic actuator, and limb knee pitch joint actuator. The auxiliary oil supply device supplies oil separately to the rod chambers of the limb knee pitch joint actuator. This design not only ensures the reliability of the position and force servo of each shut-off hydraulic cylinder during the support phase, but also improves the robot's motion efficiency during the retraction phase of the hydraulic cylinder of the knee joint pitch actuator in the swing phase.

[0017] 2. In this invention, the oil inlet circuit of the volume-adjusting hydraulic cylinder on the auxiliary oil supply device is connected to the high-pressure oil circuit of the main oil supply device, so that the auxiliary oil supply device has no external power input. The internal oil pressure comes from the volume-adjusting hydraulic cylinder with pressure adjustment function, thereby realizing a separate constant pressure oil supply to the rod chamber of the limb knee pitch joint actuator. While effectively reducing the back pressure power consumption of the rod chamber of the limb knee pitch joint actuator in the support phase, it can also provide energy for the retraction movement of the piston of the limb knee pitch joint actuator in the swing phase without power input, effectively solving the problem of low motion energy efficiency of current hydraulic quadruped robots.

[0018] 3. In this invention, a low-pressure fast-charging connector is set on the main oil supply device, and the auxiliary oil supply device and the main oil supply device are connected through an oil filling valve block assembly. The low-pressure fast-charging connector is mainly used for the oil filling operation of the system to ensure that the system has a stable base pressure and sufficient oil reserves. The oil filling valve block assembly can help the auxiliary oil supply device to continue to store high-pressure oil in the initial stage of startup. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A front-view three-dimensional structural diagram of the onboard hydraulic station of a quadruped robot;

[0021] Figure 2 This is a rear-view 3D structural diagram of the onboard hydraulic station of a quadruped robot.

[0022] Figure 3 Cross-sectional view of the main oil supply unit;

[0023] Figure 4 A cross-sectional view of the auxiliary oil supply device;

[0024] Figure 5 A three-dimensional structural diagram of the oil-filled valve block assembly;

[0025] Figure 6 This is a cross-sectional view of the oil-filled valve block assembly;

[0026] Figure 7 This is a schematic diagram of the oil circuit.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. Main oil supply device; 2. Auxiliary oil supply device; 3. Oil filling valve block assembly; 4. Electromagnetic unloading valve; 5. First fastening bolt; 6. Second fastening bolt; 7. Third fastening bolt; 8. Fourth fastening bolt; 9. Fifth fastening bolt; 10. Sixth fastening bolt; 11. Seventh fastening bolt; 12. Eighth fastening bolt; 13. Ninth fastening bolt; 14. Tenth fastening bolt; 15. Eleventh fastening bolt; 16. Three-position four-way valve I; 17. Three-position four-way valve II; 18. Three-position three-way valve; A. Hip pitch joint hydraulic actuator; B. Hip lateral swing joint hydraulic actuator; C. Knee pitch joint actuator;

[0029] 101. Accumulator; 102. Main sealed oil tank; 103. Spherical airbag; 104. Main oil tank sealing cover; 105. Main one-way air charging valve assembly; 106. Low-pressure fast charging connector; 107. Low-pressure oil outlet connector; 108. High-pressure oil return connector; 109. Main sensor bushing; 110. Main sensor friction shaft; 111. Low-pressure oil filter; 112. Low-pressure oil circuit temperature sensor; 113. Low-pressure oil circuit pressure limiting valve; 114. High-pressure oil circuit filter; 115. High-pressure oil circuit pressure limiting valve; 116. First air passage; 117. Second air passage; 118. Main liquid level adjusting piston; 119. Main piston bushing; A1. Main air chamber; B1. Main oil chamber;

[0030] 201. Hydraulic cylinder body; 202. Air chamber; 203. Auxiliary sealed oil tank; 204. Auxiliary oil tank sealing cover; 205. Auxiliary one-way air charging valve assembly; 206. Electro-hydraulic servo valve; 207. Adjusting oil inlet connector; 208. Adjusting oil outlet connector; 209. Cylinder end cover; 210. Volume adjusting piston; 211. Pressure adjusting piston; 212. Auxiliary piston bushing; 213. Auxiliary sensor bushing; 214. Auxiliary sensor friction shaft; 215. Third air passage; 216. Fourth air passage; 217. Fifth air passage; 218. High-pressure oil inlet / outlet connector; 219. Auxiliary fluid level adjusting piston; A2. Auxiliary air chamber; B2. Auxiliary oil chamber;

[0031] 301. Oil manifold block; 302. Two-position two-way directional valve; 303. High-pressure oil supply connector; 304. Oil manifold plug; 305. Process connector; a. First pipeline; b. Second pipeline; c. Third pipeline; d. Fourth pipeline; e. Fifth pipeline; f. Sixth pipeline. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This embodiment provides an onboard hydraulic station suitable for quadruped robots, such as... Figures 1 to 7 As shown, it includes a main oil supply device 1 and an auxiliary oil supply device 2, which are fixedly connected. The main oil supply device 1 and the auxiliary oil supply device 2 are mainly used for installation on quadruped robots. After the onboard hydraulic station is installed on the quadruped robot, the oil supply circuit of the main oil supply device 1 is connected to the high-pressure oil supply circuit of the quadruped robot via a hydraulic pump. The return oil circuit of the main oil supply device 1 is connected to the low-pressure return oil circuit of the quadruped robot. The low-pressure return oil circuit and the high-pressure oil supply circuit of the quadruped robot are connected to the hip pitch joint hydraulic actuator A via a three-position four-way valve I 16 to achieve oil supply and return. The low-pressure return oil circuit and the high-pressure oil supply circuit of the quadruped robot are connected to the hip side swing joint hydraulic actuator B via a three-position four-way valve II 17 to achieve oil supply and return. The low-pressure return oil circuit and the high-pressure oil supply circuit of the quadruped robot are connected to the rodless chamber of the knee pitch joint actuator C via a three-position three-way valve 18 to achieve oil supply and return. The auxiliary oil supply device 2 is equipped with a high-pressure oil inlet / outlet connector 218, which is connected to the rod chamber of the knee pitch joint actuator C to achieve oil supply and return.

[0034] This onboard hydraulic station employs a dual-supply system design. The main supply unit 1 and hydraulic pump D form a conventional hydraulic servo circuit, supplying oil to the rodless chambers of the hip pitch joint hydraulic actuator A, the hip lateral swing joint hydraulic actuator B, and the knee pitch joint actuator C. The auxiliary supply unit 2 provides separate constant-pressure oil supply to the rod chamber of the knee pitch joint actuator C. (Hydraulic principle reference) Figure 7 As shown in the diagram, the dashed lines in the linear pipeline connection diagram represent low-pressure oil circuits, and the straight lines represent high-pressure oil circuits. This design is primarily based on the unique mechanical characteristics of the knee joint. For a quadruped robot with a two-stage, three-degree-of-freedom joint structure, the load force borne by the joint actuators is only significant during the support phase, while the load force during the swing phase is smaller. Especially during the support phase, the knee joint pitch actuator C only bears a back pressure load. Therefore, the rodless chamber of the knee joint pitch actuator C is the main control chamber, and the rod chamber of the knee joint pitch actuator C only needs to ensure continuous flow. Thus, the rod chamber of the knee joint pitch actuator C is supplied with oil solely by the auxiliary oil supply device 2. This design ensures the reliability of the hydraulic cylinder position and force servo during the support phase and improves the robot's motion efficiency during the retraction phase of the hydraulic cylinder of the knee joint pitch actuator C in the swing phase.

[0035] In this embodiment, as Figures 1 to 7As shown, the main oil supply device 1 is equipped with a low-pressure oil outlet connector 107, a high-pressure oil return connector 108, and a high-pressure oil supply connector 303. The inlet end of the low-pressure oil outlet connector 107 is connected to the main oil supply device 1, and the outlet end of the low-pressure oil outlet connector 107 is connected to the low-pressure oil return circuit of the quadruped robot and the suction port of the hydraulic pump D via a three-way valve and a high-pressure hose. The low-pressure oil return circuit of the quadruped robot is connected to the low-pressure oil return circuits of three-position four-way valve I 16, three-position four-way valve II 17, and three-position three-way valve 18. The oil supply port of the hydraulic pump D is connected to the inlet end of the high-pressure oil return connector 108, and the outlet end of the high-pressure oil return connector 108 is connected to the inlet end of the high-pressure oil supply connector 303. The outlet end of the high-pressure oil supply connector 303 is used to connect to the high-pressure oil supply circuit of the quadruped robot, which is connected to the high-pressure oil supply circuits of three-position four-way valve I 16, three-position four-way valve II 17, and three-position three-way valve 18.

[0036] The low-pressure oil outlet connector 107 sends the low-pressure oil from the main oil supply device 1 into the suction port of the hydraulic pump D. After being pressurized by the hydraulic pump D, it forms high-pressure oil, which is then sent into the high-pressure return oil connector 108. The high-pressure return oil connector 108 then sends the high-pressure oil to the high-pressure supply oil connector 303, so that high-pressure oil can be supplied to the rod chambers of the hip pitch joint hydraulic actuator A, the hip lateral swing joint hydraulic actuator B, and the limb knee pitch joint actuator C through the three-position four-way valve I 16, the three-position four-way valve II 17, and the three-position three-way valve 18. The return oil from the rod chambers of the hip pitch joint hydraulic actuator A, the hip lateral swing joint hydraulic actuator B, and the limb knee pitch joint actuator C is sent back to the three-way port of the low-pressure oil outlet connector 107 through the low-pressure return oil circuit of the quadruped robot, and then sent into the suction port of the hydraulic pump D.

[0037] To further reduce energy consumption and improve the operational efficiency of the quadruped robot, in this embodiment, as follows: Figures 1 to 7As shown, the auxiliary oil supply device 2 includes a volume-adjusting hydraulic cylinder, an air chamber 202, and an auxiliary sealed oil tank 203. The air chamber 202 is connected to the auxiliary sealed oil tank 203 by a sixth fastening bolt 10. The bottom of the auxiliary sealed oil tank 203 is sealed by an auxiliary oil tank sealing cover 204, which is fixed to the bottom of the auxiliary sealed oil tank 203 by a seventh fastening bolt 11. An auxiliary oil chamber B2 is provided inside the auxiliary sealed oil tank 203, and a high-pressure oil inlet / outlet connector 218 is connected to the auxiliary sealed oil tank 203. An auxiliary air chamber A2 is provided inside the air chamber 202, and the auxiliary air chamber A2 is sealed to the auxiliary oil chamber B2 by an auxiliary piston sealing assembly. The auxiliary piston sealing assembly includes an auxiliary sealing limit ring and an auxiliary piston bushing 212, with the auxiliary sealing limit ring fixed at the end of the auxiliary oil chamber B2 near the auxiliary air chamber A2. The auxiliary piston bushing 212 is sealed within the inner ring of the auxiliary sealing limiting ring and can move up and down. An auxiliary liquid level adjusting piston 219 is fixed to the end of the auxiliary piston bushing 212. The auxiliary liquid level adjusting piston 219 is located in the auxiliary oil chamber B2. When the gas in the auxiliary gas chamber A2 is compressed, it enters the auxiliary piston bushing 212, pushing the auxiliary liquid level adjusting piston 219 to move, thereby squeezing the high-pressure oil in the auxiliary oil chamber B2. The auxiliary sealed oil tank 203 is equipped with an auxiliary one-way charging valve assembly 205 that communicates with the auxiliary gas chamber A2. Gas can be charged into the auxiliary gas chamber A2 through the auxiliary one-way charging valve assembly 205. Specifically, the auxiliary one-way charging valve assembly 205 is fixedly connected to the auxiliary sealed oil tank 203 by the fourth fastening bolt 8, and then gas is charged into the auxiliary gas chamber A2 sequentially through the third air passage 215, the fourth air passage 216, and the fifth air passage 217. The volume-adjusting hydraulic cylinder is fixed on the air chamber 202. The output shaft of the volume-adjusting hydraulic cylinder is equipped with a volume-adjusting piston 211 that extends into the auxiliary air chamber A2. The oil inlet of the volume-adjusting hydraulic cylinder is connected to the high-pressure oil supply connector 303, and the oil outlet of the volume-adjusting hydraulic cylinder is connected to the low-pressure return oil circuit of the quadruped robot. An auxiliary liquid level sensor is installed in the auxiliary oil chamber B2.

[0038] When the main oil supply device 1 supplies high-pressure oil to the outside through the high-pressure oil supply connector 303, a portion of the high-pressure oil simultaneously enters the volume-adjusting hydraulic cylinder. The volume-adjusting hydraulic cylinder determines whether its output shaft extends or retracts, thereby driving the volume-adjusting piston 211 to either compress or restore the volume of the auxiliary air chamber A2. This changes the pressure of the gas inside the auxiliary air chamber A2, balancing the pressure of the high-pressure oil in the auxiliary oil chamber B2, thus achieving constant pressure for oil supply and return to the rod chamber of the knee pitching actuator C. This design eliminates the need for external power input to the auxiliary oil supply device 2, as the internal oil pressure comes from the main oil supply device 1. This effectively reduces the back pressure power consumption of the rod chamber of the knee pitching actuator C during the support phase, while also providing energy for the retraction motion of the piston in the knee pitching actuator C during the swing phase without power input, improving motion efficiency and effectively solving the problem of low motion efficiency in current hydraulic quadruped robots.

[0039] In this embodiment, as Figures 1 to 7 As shown, the volume-adjusting hydraulic cylinder includes a hydraulic cylinder body 201 and an electro-hydraulic servo valve 206. The electro-hydraulic servo valve 206 is fixed to the hydraulic cylinder body 201, which is fixed to the air chamber 202 by a ninth fastening bolt 13. A pressure regulating piston 210 is provided inside the hydraulic cylinder body 201, dividing the interior of the hydraulic cylinder body 201 into a first injection chamber and a second injection chamber. The output shaft of the volume-adjusting hydraulic cylinder is fixed to the pressure regulating piston 210 and extends from the cylinder end cap 209 at the second injection chamber. The output shaft is connected to the volume regulating piston 211 via a threaded connection. The electro-hydraulic servo valve 206 is connected to the first injection chamber and the second injection chamber. The hydraulic cylinder body 201 is provided with an adjusting oil inlet connector 207 and an adjusting oil outlet connector 208 that are connected to the electro-hydraulic servo valve 206. The adjusting oil inlet connector 207 is connected to the high-pressure oil supply connector 303 through a high-pressure hose, and the adjusting oil outlet connector 208 is connected to the low-pressure return oil circuit of the quadruped robot through a high-pressure hose.

[0040] Operation of the variable pressure control process of auxiliary oil supply device 2: When the robot is running, the liquid levels in the auxiliary oil chamber B2 of auxiliary oil supply device 2 and the main oil chamber B1 of main oil supply device 1 are dynamically changing. In order to maintain constant pressure in auxiliary oil supply device 2, according to the detection signal of liquid level sensor, part of the high pressure oil in high pressure supply connector 303 enters electro-hydraulic servo valve 206 through adjusting oil inlet connector 207, and sequentially enters the corresponding working chamber (first injection chamber or second injection chamber) through the internal oil passage of electro-hydraulic servo valve 206 and hydraulic cylinder body 201, pushing pressure regulating piston 210 to move, thereby driving volume regulating piston 211 to move up and down, thereby changing the internal volume of auxiliary air chamber A2, thereby changing the pressure environment inside auxiliary air chamber A2, changing the pressure on the auxiliary liquid level regulating piston 219 at the end of auxiliary piston sleeve 212, thereby squeezing or releasing the pressure of high pressure oil in auxiliary oil chamber B2, and realizing constant pressure oil supply.

[0041] The auxiliary liquid level detector can be a commonly available liquid level sensor, as long as it can detect the hydraulic oil level in the auxiliary oil chamber B2. This embodiment provides a specific structure for the auxiliary liquid level detector, as follows: Figures 1 to 7As shown, the auxiliary liquid level detector includes an auxiliary sensor sleeve 213 and an auxiliary sensor friction shaft 214. The auxiliary sensor sleeve 213 is fitted inside the auxiliary piston sleeve 212 and fixedly connected to the auxiliary liquid level adjusting piston 219. The auxiliary sensor friction shaft 214 is fixed inside the auxiliary oil chamber B2, preferably fixed to the auxiliary oil tank sealing cover 204. The auxiliary liquid level adjusting piston 219 is provided with an auxiliary sealing guide hole for the auxiliary sensor friction shaft 214 to extend into the auxiliary sensor sleeve 213. The auxiliary sensor sleeve 213 is slidably connected to the auxiliary sensor friction shaft 214 and generates friction with it. The liquid level in the auxiliary oil chamber B2 rises and falls, pushing the auxiliary liquid level adjusting piston 219 to rise and fall, thereby driving the auxiliary sensor sleeve 213 to rise and fall, changing the relative position of the auxiliary sensor friction shaft 214 and the auxiliary sensor sleeve 213. Through the variable resistance effect generated by the position change, the liquid level height in the auxiliary oil chamber B2 can be measured.

[0042] In this embodiment, as Figures 1 to 7 As shown, the main oil supply device 1 includes an accumulator 101 and a main sealed oil tank 102. The accumulator 101 and the main sealed oil tank 102 are directly connected by the eighth fastening bolt 12. The lower end face of the main sealed oil tank 102 is sealed by the main oil tank sealing cover 104, which is connected to the main oil tank sealing cover 104 by the tenth fastening bolt 14. The main sealed oil tank 102 and the auxiliary sealed oil tank 203 are connected by the first fastening bolt 5. The accumulator 101 is provided with a spherical air bladder 103 for forming the main gas chamber A1. The main sealed oil tank 102 is provided with a main oil chamber B1, which is sealed to the main gas chamber A1 through the main piston sealing assembly. The main piston sealing assembly includes a sealing limiting ring and a main piston bushing 119. The sealing limiting ring is fixed at one end of the main oil chamber B1 near the main gas chamber A1, and the main piston bushing 119 is sealed within the inner ring of the main sealing limiting ring. A main liquid level adjusting piston 118 is fixed to the end of the main piston bushing 119. The main sealed oil tank 102 is equipped with a main one-way air charging valve assembly 105 that communicates with the main gas chamber A1. The main one-way air charging valve assembly 105 is connected to the main sealed oil tank 102 by a fifth fastening bolt 9, and then charges the auxiliary gas chamber A2 through the first air passage 116 and the second air passage 117 in sequence. The low-pressure oil outlet connector 107 communicates with the main oil chamber A1, and a main liquid level sensor is installed in the main oil chamber A1.

[0043] Furthermore, in this embodiment, as Figures 1 to 7As shown, the main liquid level detector includes a main sensor sleeve 109 and a main sensor friction shaft 110. The main sensor sleeve 109 is located inside the main piston sleeve 119 and is fixedly connected to the main liquid level adjusting piston 118. The main sensor friction shaft 110 is fixed inside the main oil chamber B1, preferably fixed on the main oil tank sealing cover 104. The main liquid level adjusting piston 118 is provided with a main sealing guide hole for the main sensor friction shaft 110 to extend into the main sensor sleeve 109. The main sensor sleeve 109 is slidably connected to the main sensor friction shaft 110 and can generate friction with it. By utilizing the variable resistance effect generated by the change in the relative position of the main sensor friction shaft 110 and the main sensor sleeve 109, the liquid level height in the main oil chamber B1 can be measured.

[0044] In this embodiment, as Figures 1 to 7 As shown, the main sealed oil tank 102 is equipped with a low-pressure quick-charge connector 106 that communicates with the main oil chamber A1. The auxiliary sealed oil tank 203 is equipped with a high-pressure filling port that communicates with the auxiliary oil chamber B2. The high-pressure filling port is connected to the high-pressure oil supply connector 303 through the filling valve block assembly 3, which helps the auxiliary sealed oil tank 203 to continue storing high-pressure oil during the initial stage of startup. The low-pressure quick-charge connector 106 is mainly used for the oil filling operation of the system to ensure that the system has a stable base pressure and sufficient oil reserve. In order to ensure that the pressure of the hydraulic system is adjustable and the status is monitorable, a low-pressure oil filter 111, a low-pressure oil circuit pressure relief valve 113, and a low-pressure oil circuit temperature sensor 112 are connected in series between the low-pressure quick-charge connector 106 and the main oil chamber A1. The low-pressure oil circuit pressure relief valve 113 is mainly used to limit the pressure of the oil in the main oil chamber B1 to not exceed the maximum withstand pressure of the hydraulic pump D. The low-pressure oil circuit temperature sensor 112 is mainly used to detect the system oil temperature. If the temperature exceeds the rated operating temperature of the oil, the robot's main control system will issue a warning message and take measures to stop the robot for maintenance to ensure the safe operation of the robot. The low-pressure oil filter 111 is mainly used to perform fine filtration on the oil entering the system. A high-pressure oil circuit pressure relief valve 115 and a high-pressure oil circuit filter 114 are sequentially installed between the high-pressure return oil connector 108 and the high-pressure oil supply connector 303. The high-pressure oil circuit pressure relief valve 115 is used to limit the high-pressure oil circuit supply pressure to not exceed the system limit value, and the high-pressure oil circuit filter 114 is used to perform secondary fine filtration on non-input impurities that may appear in the oil circuit.

[0045] In this embodiment, as Figures 1 to 7As shown, the oil filling valve block assembly 3 includes an oil passage block 301 and a two-position two-way directional valve 302. One end of the oil passage block 301 is connected to the auxiliary sealed oil tank 203 via a second fastening bolt 6, and the other end of the oil passage block 301 is connected to the auxiliary sealed oil tank 203 via a third fastening bolt 7. The two-position two-way directional valve 302 is connected to the oil passage block 301 via an eleventh fastening bolt 15. A high-pressure oil supply connector 303 is fixed to the oil passage block 301. The oil passage block 301 is provided with a first pipeline a, a second pipeline b, a third pipeline c, a fourth pipeline d, and a fifth pipeline e. The inlet end of the first pipeline a is connected to the high-pressure oil filter 114, and the inlet end of the first pipeline a is connected to the high-pressure oil supply connector 303. The inlet end of the second pipeline b is connected to the outlet end of the first pipeline a, and the outlet end of the second pipeline b is connected to the inlet end of the third pipeline c. The outlet of the third pipeline c is connected to the inlet of the two-position two-way directional valve 302, and the outlet of the two-position two-way directional valve 302 is connected to the inlet of the fourth pipeline d. The outlet of the fourth pipeline d is connected to the inlet of the fifth pipeline e, and the outlet of the fifth pipeline e is connected to the high-pressure oil filling port, through which the fluid is fed into the auxiliary oil chamber B2.

[0046] Furthermore, in this embodiment, as Figures 1 to 7 As shown, the oil circuit block 301 is also provided with a sixth pipe f, which is connected to the fourth pipe d. The sixth pipe f is a process pipe. The second pipe b also has a process port. The sixth pipe f and the second pipe b are used to connect the internal oil circuit of the oil circuit block 301. The process port of the second pipe b is provided with a process connector 305. The sixth pipe f is plugged with an oil circuit plug 304.

[0047] In this embodiment, as Figures 1 to 7 As shown, an electromagnetic unloading valve 4 is connected between the high-pressure oil circuit (supply oil circuit) and the low-pressure oil circuit (return oil circuit) of the main oil supply device 1.

[0048] In this embodiment, as Figures 1 to 7 As shown, the operating procedure for the onboard hydraulic station is as follows:

[0049] ① Inflation process operation: When inflating the main air chamber A1 of the main oil supply device 1, the air source is connected to the main one-way inflation valve group 105. The gas enters the main air chamber A1 through the internal air passage of the main one-way inflation valve group 105, and then sequentially through the first air passage 116 and the second air passage 117 inside the main sealed oil tank 102. When inflating the auxiliary air chamber A2 of the auxiliary oil supply device 2, the air source is connected to the auxiliary one-way inflation valve group 205. The gas enters the auxiliary air chamber A2 through the internal third air passage 215 of the auxiliary one-way inflation valve group 205, and then sequentially through the fourth air passage 216 and the fifth air passage 217.

[0050] ② Oil filling process operation: The two-position two-way reversing valve 302 is de-energized, the oil passages of the main oil supply device 1 and the auxiliary oil supply device 2 are cut off, the external oil source is connected to the low-pressure fast charging connector 106, and the oil enters the main oil chamber B1 through the low-pressure oil filter 111. The entry of the oil causes the main liquid level adjusting piston 118 in the main oil chamber B1 to rise, and the main sensor bushing 109 and the main sensor friction shaft 110 slide relative to each other, thereby generating a voltage signal to measure the degree of liquid level rise. Then, the two-position two-way reversing valve 302 is energized and reversed, so that the high-pressure oil circuits of the main oil supply device 1 and the auxiliary oil supply device 2 are connected through the internal oil passage of the oil filling valve block group 3. The high-pressure oil discharged from the high-pressure oil circuit filter 114 is sequentially sent into the auxiliary oil chamber B2 through the first channel a, the second channel b, the third channel c, the fourth channel b, the fifth channel e and the high-pressure oil filling port. The liquid level in the auxiliary oil chamber B2 rises and falls, pushing the auxiliary liquid level adjusting piston 219 to rise and fall, thereby driving the auxiliary sensor bushing 213 to rise and fall, changing the relative position of the auxiliary sensor friction shaft 214 and the auxiliary sensor bushing 213. Through the variable resistance effect generated by the position change, the liquid level height in the auxiliary oil chamber B2 can be measured. When the liquid level in the oil chamber (B) reaches the specified height, the two-position two-way reversing valve 302 is de-energized and closed, and the liquid level in the main oil chamber B1 and the auxiliary oil chamber B2 stops changing.

[0051] ③ Hydraulic station shutdown and unloading operation: When the robot stops, the electromagnetic unloading valve 4 is energized and opened, connecting the high-pressure and low-pressure oil circuits of the main oil supply device 1 for unloading. At the same time, the two-position two-way reversing valve 302 is energized, and the auxiliary oil chamber B2 of the auxiliary oil supply device 2 is connected to the high-pressure oil circuit through the oil filling valve block group 3. The high-pressure oil inside the auxiliary oil chamber B2 flows back to the main oil chamber B1 of the main oil supply device 1 through the above channels. Then, the main oil chamber B1 flows into the robot's low-pressure pipeline, and the auxiliary liquid level adjusting piston 219 in the auxiliary oil chamber B2 descends to the lowest position, causing the volume of the auxiliary oil chamber B2 to return to zero. At the same time, the output shaft of the volume-adjusting hydraulic cylinder retracts to its shortest position under the control of the electro-hydraulic servo valve 206. At this time, the volume of the auxiliary gas chamber A2 is the largest, the internal gas pressure is the smallest, and the pressure in the entire system is in the initial low-pressure safety state.

[0052] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An onboard hydraulic station suitable for quadruped robots, characterized in that, The system includes a main oil supply device and an auxiliary oil supply device for mounting on the quadruped robot. The main oil supply device and the auxiliary oil supply device are fixedly connected. The main oil supply device is connected to the low-pressure return oil circuit of the quadruped robot and to the high-pressure oil supply circuit of the quadruped robot via a hydraulic pump. The low-pressure return oil circuit and the high-pressure oil supply circuit of the quadruped robot supply oil and return oil to the rodless chambers of the hip pitch joint hydraulic actuator, the hip lateral swing joint hydraulic actuator, and the knee pitch joint actuator of the quadruped robot respectively through a three-position four-way valve I, a three-position four-way valve II, and a three-position three-way valve. The auxiliary oil supply device is provided with a high-pressure oil inlet and outlet connector for supplying and returning oil to the rod chamber of the knee pitch joint actuator. The main oil supply device is equipped with a low-pressure oil outlet connector, a high-pressure oil return connector, and a high-pressure oil supply connector. The inlet end of the low-pressure oil outlet connector is connected to the main oil supply device. The outlet end of the low-pressure oil outlet connector is connected to the low-pressure oil return circuit of the quadruped robot and the oil suction port of the hydraulic pump through a T-junction. The oil supply port of the hydraulic pump is connected to the inlet end of the high-pressure oil return connector. The outlet end of the high-pressure oil return connector is connected to the inlet end of the high-pressure oil supply connector. The outlet end of the high-pressure oil inlet connector is used to connect the high-pressure oil supply circuit of the quadruped robot. The auxiliary oil supply device includes an air chamber with an auxiliary air chamber, an auxiliary sealed oil tank with an auxiliary oil chamber, and a volume-adjusting hydraulic cylinder mounted on the air chamber. The auxiliary air chamber is sealed to the auxiliary air chamber via an auxiliary piston sealing assembly. The auxiliary piston sealing assembly includes an auxiliary sealing limiting ring fixed to one end of the auxiliary oil chamber near the auxiliary air chamber, and an auxiliary piston sleeve sealed within the auxiliary sealing limiting ring. An auxiliary liquid level adjusting piston located inside the auxiliary oil chamber is fixed to the end of the auxiliary piston sleeve. The auxiliary sealed oil tank is equipped with an auxiliary one-way air filling valve assembly communicating with the auxiliary air chamber. The high-pressure oil inlet / outlet connector is connected to the auxiliary sealed oil tank. The output shaft of the volume-adjusting hydraulic cylinder is equipped with a volume adjusting piston extending into the auxiliary air chamber. The oil inlet of the volume-adjusting hydraulic cylinder is connected to the high-pressure oil supply connector, and the oil outlet of the volume-adjusting hydraulic cylinder is connected to the low-pressure return oil circuit of the quadruped robot. An auxiliary liquid level sensor is installed inside the auxiliary oil chamber.

2. The airborne hydraulic station for a quadruped robot according to claim 1, characterized in that, The volume-adjusting hydraulic cylinder includes a hydraulic cylinder body and an electro-hydraulic servo valve. The hydraulic cylinder body is provided with a pressure regulating piston that can divide its interior into a first injection chamber and a second injection chamber. The output shaft of the volume-adjusting hydraulic cylinder is fixed on the pressure regulating piston. The electro-hydraulic servo valve communicates with the first injection chamber and the second injection chamber. The hydraulic cylinder body is provided with an adjusting oil inlet connector and an adjusting oil outlet connector that communicate with the electro-hydraulic servo valve. The adjusting oil inlet connector is connected to the high-pressure oil supply connector, and the adjusting oil outlet connector is connected to the low-pressure return oil circuit of the quadruped robot.

3. The onboard hydraulic station for a quadruped robot according to claim 2, characterized in that, The auxiliary liquid level detector includes an auxiliary sensor bushing and an auxiliary sensor friction shaft. The auxiliary sensor bushing is disposed inside the auxiliary piston bushing and is fixedly connected to the auxiliary liquid level adjusting piston. The auxiliary sensor friction shaft is fixed inside the auxiliary oil chamber. The auxiliary liquid level adjusting piston is provided with an auxiliary sealing guide hole for the auxiliary sensor friction shaft to extend into the auxiliary sensor bushing. The auxiliary sensor bushing is slidably connected to the auxiliary sensor friction shaft.

4. The airborne hydraulic station for a quadruped robot according to claim 3, characterized in that, The main oil supply device includes an accumulator and a main sealed oil tank. The accumulator contains a spherical air bladder for forming the main gas chamber. The main sealed oil tank contains a main oil chamber, which is sealed to the main gas chamber via a main piston sealing assembly. The main piston sealing assembly includes a main sealing limiting ring fixed to one end of the main oil chamber near the main gas chamber, and a main piston bushing sealed within the main sealing limiting ring. A main liquid level adjusting piston located inside the main oil chamber is fixed to the end of the main piston bushing. The main sealed oil tank is equipped with a main one-way air charging valve assembly communicating with the main gas chamber, and a low-pressure oil outlet connector communicating with the main oil chamber. A main liquid level sensor is installed inside the main oil chamber.

5. An onboard hydraulic station suitable for quadruped robots according to claim 4, characterized in that, The main liquid level detector includes a main sensor bushing and a main sensor friction shaft. The main sensor bushing is disposed inside the main piston bushing and is fixedly connected to the main liquid level adjusting piston. The main sensor friction shaft is fixed inside the main oil chamber. The main liquid level adjusting piston is provided with a main sealing guide hole for the main sensor friction shaft to extend into the main sensor bushing. The main sensor bushing is slidably connected to the main sensor friction shaft.

6. An onboard hydraulic station suitable for quadruped robots according to claim 5, characterized in that, The main sealed oil tank is equipped with a low-pressure fast charging connector that communicates with the main oil chamber, and the auxiliary sealed oil tank is equipped with a high-pressure oil filling port that communicates with the auxiliary oil chamber. The high-pressure oil filling port is connected to the high-pressure oil supply connector through an oil filling valve block assembly. A low-pressure oil filter, a low-pressure oil circuit pressure limiting valve, and a low-pressure oil circuit temperature sensor are connected in series between the low-pressure fast charging connector and the main oil chamber. A high-pressure oil circuit pressure limiting valve and a high-pressure oil filter are connected in series between the high-pressure oil return connector and the high-pressure oil supply connector.

7. An onboard hydraulic station suitable for quadruped robots according to claim 6, characterized in that, The oil filling valve block assembly includes an oil passage block and a two-position two-way reversing valve. The oil passage block is provided with a first pipeline, a second pipeline, a third pipeline, a fourth pipeline, and a fifth pipeline. The high-pressure oil supply connector is disposed on the oil passage block and is connected to the outlet end of the first pipeline. The inlet end of the first pipeline is connected to the high-pressure return oil connector. The outlet end of the first pipeline is connected to the high-pressure oil supply connector. The inlet end of the second pipeline is connected to the outlet end of the first pipeline. The outlet end of the second pipeline is connected to the inlet end of the third pipeline. The outlet end of the third pipeline is connected to the inlet end of the two-position two-way reversing valve. The outlet end of the two-position two-way reversing valve is connected to the inlet end of the fourth pipeline. The outlet end of the fourth pipeline is connected to the inlet end of the fifth pipeline. The outlet end of the fifth pipeline is connected to the high-pressure oil filling port.

8. An onboard hydraulic station for a quadruped robot according to claim 5, characterized in that, An electromagnetic unloading valve is connected between the oil supply circuit and the oil return circuit of the main oil supply device.

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