CN108518368B

CN108518368B - Valve control hydraulic transmission system applied to exoskeleton robot

Info

Publication number: CN108518368B
Application number: CN201810421622.XA
Authority: CN
Inventors: 侯刚; 王海波; 曹雄; 曹明远; 杨毛; 王佩瑾
Original assignee: Guiyang Haizhili Hydraulic Co ltd
Current assignee: Guiyang Haizhili Hydraulic Co ltd
Priority date: 2018-05-04
Filing date: 2018-05-04
Publication date: 2023-09-19
Anticipated expiration: 2038-05-04
Also published as: CN108518368A

Abstract

The invention discloses a valve-controlled hydraulic transmission system applied to an exoskeleton robot, which comprises a hydraulic oil source, a manual servo valve, an oil supplementing one-way valve, an oil cylinder, a first mechanical arm and a second mechanical arm hinged with the first mechanical arm, wherein the hydraulic oil source is connected with the manual servo valve; the hydraulic oil source comprises a servo motor, a hydraulic pump and an oil tank, wherein the servo motor drives the hydraulic pump, and the hydraulic pump absorbs oil from the oil tank and supplies oil to the manual servo valve; the manual servo valve is provided with mechanical position feedback to form closed-loop control, an oil outlet of the manual servo valve is communicated with an oil inlet cavity of the oil cylinder, and the oil outlet is also communicated with the oil tank through an oil supplementing one-way valve; the manual servo valve comprises a reversing valve, a reversing operating mechanism connected with the reversing valve and an operating mechanism travel limiting device. According to the invention, under the combined action of the manual servo valve, the oil supplementing one-way valve and the oil cylinder, the control mode of the exoskeleton robot is simplified, the working reliability and the safety are effectively improved, the energy consumption is reduced, the working speed is improved, and the production and use cost is reduced.

Description

Valve control hydraulic transmission system applied to exoskeleton robot

Technical Field

The invention relates to the technical field of mechanical engineering, in particular to a valve-controlled hydraulic transmission system applied to an exoskeleton robot.

Background

The exoskeleton robot is a man-machine cooperation device worn on a human body, and has wide application prospects in the fields of military, logistics, rescue, disability assistance and the like. Several institutions at home and abroad have developed exoskeleton robots and obtained staged research results.

The exoskeleton robot is divided into three types, namely electric transmission (a motor driven speed reducer or a screw rod), hydraulic transmission (a hydraulic oil driven oil cylinder), pneumatic transmission (a compressed air driven air cylinder) and the like. Among them, the hydraulic transmission is a mainstream transmission scheme on a heavy-duty (load-bearing) exoskeleton robot because of its high power density and large output force.

The hydraulic transmission exoskeleton robot generally adopts electrohydraulic servo valves to control the running direction and running speed of each oil cylinder. For example: the application publication No. CN 105496734A discloses a follow-up system based on the action state of a mechanical exoskeleton, the grant publication No. CN 103612257B discloses an exoskeleton pump valve combined control device and control method, the grant publication No. CN 105798932B discloses a control method for the walking state of an exoskeleton system and the like, which relate to the hydraulic transmission and control of an exoskeleton robot and all adopt electrohydraulic servo valves.

The hydraulic transmission and control schemes in the above patent documents differ in specific details, but share several common features:

1) An electrohydraulic servo valve is adopted to control the operation speed and the operation direction of the oil cylinder;

2) Installing various sensors, and identifying the movement intention of the human body by collecting sensor information and comprehensively analyzing;

3) The input command of the electrohydraulic servo valve is given by a complex algorithm.

These common features make it deficient in several ways:

1. the transmission efficiency is low. The electrohydraulic servo valve is a control element for replacing high response speed by sacrificing energy consumption, when the flow is required to be accurately controlled (corresponding to the speed control of the oil cylinder), a valve port must maintain certain pressure loss, and pilot oil consumption (the proportion of the pilot oil consumption is larger for miniature hydraulic transmission) exists, so that the hydraulic system controlled by the electrohydraulic servo valve has the common problems of low transmission efficiency and high non-efficient energy consumption. The higher non-efficient energy consumption can cause the system to generate heat, and additional heat dissipation measures are needed, so that the energy consumption is further increased, the overall appearance and weight of the exoskeleton robot are increased, and the battery endurance time is shortened.

2. The control is complex, the factors restricting the realization of the functions are excessive, and the working condition adaptability and the working reliability are reduced. The control source of the mechanical arm motion comes from a plurality of sensors for detecting the working states of the human body and the mechanical arm, the control instruction of the electrohydraulic servo valve is calculated by collecting the information of the plurality of sensors, comparing and analyzing, and then calling a complex control algorithm. During operation, any failure of the associated hardware or software can result in failure of the control, with more associated factors providing more potential points of failure. Moreover, because the motion postures of the people are various, the control based on the preset algorithm is difficult to comprehensively cover all possible motion postures of the wearer, and the working condition adaptability of the wearer is affected.

3. The manufacturing cost is too high, and the market popularization is restricted. Because of the need to configure a plurality of servo valves, a plurality of sensors and a processor (or microcomputer) with stronger functions, on one hand, an installation space is reserved for the components, which can lead to the increase of the overall appearance and weight; on the other hand, these components themselves are of higher value, further increasing the manufacturing costs. While performance may be of great concern in the development stage, and cost control is put on its own, to form a commodity, controlling manufacturing costs is a matter of time.

Therefore, how to provide a low-cost hydraulic transmission control device which is simple to control, reliable in operation, less in energy consumption and applied to an exoskeleton robot is a problem to be solved by those skilled in the art.

Disclosure of Invention

In view of the above, the invention provides a valve-controlled hydraulic transmission system applied to an exoskeleton robot, which simplifies a control mode, effectively improves working reliability and safety, reduces energy consumption, improves working speed and reduces production and use costs under the combined action of a manual servo valve, an oil supplementing one-way valve and an oil cylinder.

11. In order to achieve the above purpose, the present invention adopts the following technical scheme: a valve-controlled hydraulic transmission system for an exoskeleton robot, comprising: the hydraulic oil source, the manual servo valve, the oil supplementing one-way valve, the oil cylinder and the mechanical arm;

The hydraulic oil source comprises a servo motor, a hydraulic pump and an oil tank, wherein the servo motor drives the hydraulic pump, and the hydraulic pump absorbs oil from the oil tank and supplies oil to the manual servo valve;

the manual servo valve is provided with mechanical position feedback to form closed-loop control, and is provided with at least one oil inlet, one oil return port and one oil outlet, wherein the oil outlet is communicated with an oil inlet cavity of the oil cylinder, and the oil outlet is also communicated with the oil tank through an oil supplementing one-way valve;

the manual servo valve is arranged on the exoskeleton robot and comprises a reversing valve, a reversing operating mechanism and an operating mechanism travel limiting device, wherein the reversing operating mechanism is connected with the reversing valve;

the reversing control mechanism is at least one point tied on a limb of a person and comprises a control rod, wherein at least one point of the control rod is directly or indirectly connected with the mechanical arm, and when the relative position of the control rod and the mechanical arm is in an initial state, the reversing valve of the manual servo valve is in a middle position;

when a wearer manipulates the first control lever or the second control lever through limbs, the relative position of the control lever and the mechanical arm generates deviation from an initial state, the deviation drives the reversing valve to reverse, the direction of the deviation determines the reversing direction of the reversing valve, and the magnitude of the deviation is positively correlated with the opening of the valve port of the reversing valve;

After the deviation drives the reversing valve to change direction, the hydraulic oil source drives the oil cylinder to enable the first mechanical arm and the second mechanical arm to generate relative motion, and the direction of the relative motion tends to gradually reduce the deviation until the reversing valve returns to the middle position again after the deviation is completely eliminated;

the control mechanism of the manual servo valve is provided with a control mechanism travel limiting device, the limiting device is arranged on the exoskeleton robot and used for limiting the maximum travel of the control rod, namely limiting the maximum deviation of the control rod and the mechanical arm, the limiting device can be in the form of a limit stop or a limit screw and the like, and when the control mechanism is limited by the control mechanism travel limiting device, the limbs of a wearer of the exoskeleton robot can drive the mechanical arm to move through the control mechanism.

Preferably, the reversing operating mechanism comprises a first operating lever and a second operating lever which are connected with each other, and the mechanical arm comprises a first mechanical arm and a second mechanical arm hinged with the first mechanical arm; the first control rod is directly or indirectly connected with the first mechanical arm at least at one point, the second control rod is directly or indirectly connected with the second mechanical arm at least at one point, and when the relative position of the first control rod and the first mechanical arm and the relative position of the second control rod and the second mechanical arm are in an initial state, the reversing valve of the manual servo valve is in a middle position;

The relative position of the first control rod and the first mechanical arm or/and the relative position of the second control rod and the second mechanical arm generates deviation from an initial state, the deviation drives the reversing valve to reverse, the direction of the deviation determines the reversing direction of the reversing valve, and the magnitude of the deviation is positively correlated with the opening of the valve port of the reversing valve.

Preferably, when the first mechanical arm does not act, the deviation generated between the relative position of the second control lever and the second mechanical arm and the initial state drives the reversing valve to reverse, and the first control lever does not act; or when the second mechanical arm does not act, the deviation generated between the relative position of the first control lever and the first mechanical arm and the initial state drives the reversing valve to reverse, and the second control lever does not act.

Preferably, the oil cylinder is a single-acting oil cylinder or a double-acting oil cylinder.

Preferably, the manual servo valve is a three-position four-way manual servo valve and is provided with two oil outlets, and the two oil outlets are respectively communicated with a rodless cavity and a rod cavity of the double-acting oil cylinder; or one of the two oil outlets is communicated with the oil inlet cavity of the single-acting oil cylinder.

Preferably, the manual servo valve is a three-position three-way manual servo valve and is provided with an oil outlet, and the oil outlet is communicated with an oil inlet cavity of the single-acting oil cylinder.

Preferably, the outlet of the hydraulic pump is connected to a high pressure accumulator via a one-way valve to boost the instantaneous power of the exoskeleton robot.

Preferably, a power-assisted function switching valve is arranged on an oil inlet path of the manual servo valve, wherein each manual servo valve is provided with one power-assisted function switching valve, or a plurality of manual servo valves are grouped, each group of manual servo valve oil inlet paths share one power-assisted function switching valve, and the control mode of the power-assisted function switching valve comprises forced opening or closing of a wearer.

Preferably, the hydraulic oil source further comprises a low-pressure oil source, and oil is supplied to the oil outlet of the power assisting function switching valve through a one-way valve.

Preferably, the power assisting device further comprises a force sensor, wherein the force sensor is used for detecting the actual stress of the human body limb, comparing the actual stress with a preset value set by the exoskeleton robot controller to determine the working position of the power assisting function switching valve, closing the power assisting function switching valve when the actual stress of the human body limb is smaller than or equal to a first preset value, and opening the power assisting function switching valve when the actual stress of the human body limb is larger than or equal to a second preset value.

Preferably, the manual servo valve and the oil supplementing one-way valve corresponding to the manual servo valve are integrally designed.

Preferably, when the scheme is applied to the assistance of a plurality of joints of a human body, the oil cylinders of the joints share a hydraulic oil source.

Preferably, the oil tank is a closed elastic oil tank.

Preferably, when only one of the two mechanical arms moving relatively is required to move actively, the reversing control mechanism of the manual servo valve is provided with only one control lever, and at least one point of the control lever is directly or indirectly connected with the mechanical arm moving actively and at least one point of the control lever is bound on a limb of a person.

According to the technical scheme, the hydraulic transmission control device of the exoskeleton robot is simpler and more reliable in control, lower in energy consumption, higher in working speed and lower in cost. The method has the following specific beneficial effects:

1. simple control

The exoskeleton robot is used as a man-machine cooperation device, and the core control requirement is to coordinate the human body action and the machine action. In addition to some special uses (e.g., disability) requiring the human body to follow the movement of the machine, it is required for most uses that the machine follow the movement of the human body. The core of the negative exoskeleton robot is that the robot can follow the human body motion in real time no matter what control strategy is adopted and what type of sensor is arranged to detect, analyze and identify the human body motion intention. Compared with the conventional scheme, the invention adopts the simplest and direct mode, namely, the mechanical contact between the human body limb and the control input end of the manual servo valve, so that the mechanical arm moves along with the human body limb, multiple sensors are not required to be arranged to detect the state and movement trend of the human body limb, a complex algorithm is not required, and a powerful controller is not required (the invention has lower requirements on the controller).

2. Reliable operation

The operational reliability advantages of the present invention relative to conventional solutions can be manifested in several ways:

1) Because the control is simple, a plurality of sensors are not required to be installed, a complex algorithm and a powerful controller are not required, namely, the number of precision components used by the method is smaller, and potential fault points are fewer.

2) In the scheme of the invention, under the joint action of the manual servo valve, the oil supplementing one-way valve and the reversing control mechanism limiting device, a wearer can override the exoskeleton robot by using self force under emergency conditions, and the device is not limited by the instantaneous maximum oil supply flow of the exoskeleton robot, the response speed of components and any control program.

The present invention accomplishes this function based on several requirements: firstly, when the oil cylinder is not followed in time, the limbs of a wearer can forcedly drive the mechanical arm to move through the operating rod tied on the limbs of a human body; secondly, when the mechanical arm is driven to move forcedly, if the oil absorption of the oil cylinder is insufficient, the oil supplementing one-way valve can ensure that the oil cylinder absorbs the oil smoothly; thirdly, when the wearer needs to forcedly drive the mechanical arm to move, the manual servo valve is in a reversing state, the working position of the reversing valve and the opening of the valve port are in accordance with expectations, and if oil is discharged by the oil cylinder, the oil discharge path is also smooth. The function of the invention has strong practical value for improving the working reliability and the working safety, and the invention specifically comprises the following steps:

When some emergency conditions are encountered, such as stumble on the sole of a foot, the human body needs to make a quick response when the human body is about to lose balance, and at the moment, the action speed of the human body is not limited by the instantaneous maximum oil supply flow of the hydraulic oil source or factors such as a control program, so that the gait can be adjusted in time to find balance again, and falling is avoided. This actually improves the safety and reliability of the exoskeleton robot.

The wearer can walk quickly under the no-load state without being limited by the instantaneous maximum oil supply flow of the hydraulic oil source, so that various emergency demands can be met, such as running to a rescue place quickly in the rescue process.

The safety of the wearer can also be improved in the event of a failure of the assistance system. For example, when the energy consumption of the battery in the rescue scene is finished, all the electric control devices are out of operation, and at the moment, the wearer can at least walk normally (without taking any temporary measures) although the exercise burden is increased, and the electric control devices cannot be trapped in place.

3. The energy consumption is smaller

The scheme of the invention has smaller energy consumption, and the invention has the following characteristics:

the manual servo valve used in the invention has no additional energy loss caused by pilot energy consumption. The conventional scheme adopts electrohydraulic servo valve control, and a hydraulic amplifier has pilot oil consumption loss. The pilot oil consumption loss has a smaller proportion on the high-power hydraulic system, and the influence on the whole energy consumption is negligible. However, in the case of hydraulically driven exoskeleton robots, the hydraulic system itself is in the micro hydraulic category, the power is low, and the energy loss due to the pilot fuel consumption is relatively high with respect to the specific gravity of the rated power of the system.

According to the manual servo valve used in the scheme, the opening of the valve port is automatically adjusted according to the deviation between the limbs of the human body and the mechanical arm, and the valve port is not required to maintain certain pressure loss, so that the system pressure only needs to meet the acceleration requirement. When the electrohydraulic servo valve is adopted for control, the opening of the valve port is required to be adjusted according to the deviation between the limb of the human body and the mechanical arm according to a preset algorithm, and the system pressure is required to be slightly higher than the inlet pressure of the oil cylinder to ensure that the valve port of the electrohydraulic servo valve maintains a certain pressure difference, so that the energy consumption is increased.

The electrohydraulic servo valve and various sensors adopted by the conventional scheme are required to consume power, but the invention only needs to use a force sensor, does not need other various sensors for detecting the body limb state and the mechanical arm state, and does not consume electric energy (the operating force of the reversing valve is very small and the physical consumption of the body is negligible), so the invention consumes much less electric energy in control.

In addition, the power-assisted function switching valve and measures such as auxiliary oil supply of a low-pressure oil source are also beneficial to reducing the whole energy consumption level.

4. The working speed is faster

As described above, when the scheme of the invention is adopted, a wearer can override the exoskeleton robot by using the self-force, the limitation of the instantaneous maximum oil supply flow of the exoskeleton robot is avoided, the limitation of the response speed of components is avoided, and the limitation of any control program is avoided. The function is not only beneficial to improving the working reliability and safety, but also can actually improve the working efficiency. For example, even if the exoskeleton robot is in a load-bearing state, the exoskeleton robot can be free from the limitation of the oil supply flow of the system when the non-load-bearing leg is lifted and stepped, and can rapidly lift and step, so that the overall walking speed is improved; in the light load state, the wearer is not limited by the response speed of the components, and even fast running can be realized. Although the physical energy consumption of a human body can be increased by forcibly driving the mechanical arm to move by the human body under the condition that the design speed is far beyond that of the mechanical arm, the function still has strong practical significance, for example, the working speed is very necessary to be improved in a short time when emergency rescue or emergency refuge is carried out.

5. Lower cost

The invention does not need to use an expensive electrohydraulic servo valve, has a relatively small number of sensors and has a much lower requirement on a controller, so that the overall cost is lower, which is obvious.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of an embodiment of the present invention employing a double acting cylinder for knee joint assistance;

FIG. 2 is a diagram illustrating the operating principle of the manual servo valve and the mechanical position feedback thereof according to the present invention;

FIG. 3 is a schematic view of a first embodiment of the hydraulic oil source of the present invention;

FIG. 4 is a schematic diagram of an embodiment of the present invention employing a single-acting cylinder to assist the knee joint;

FIG. 5 is a schematic view of a second embodiment of the hydraulic oil source of the present invention;

FIG. 6 is a schematic view of a third embodiment of a hydraulic oil source according to the present invention;

FIG. 7 is a schematic view of a fourth embodiment of a hydraulic oil source according to the present invention;

figure 8 is a schematic diagram of a complete embodiment of the present invention for assisting lower limbs.

In the case of the view of figure 1,

1 is a hydraulic oil source; 2 is an oil supplementing one-way valve; 3 is a manual servo valve; 4 is an oil cylinder; 10 is a first mechanical arm; 20 is a second mechanical arm;

in the case of the figure of the drawings in which,

31 is a reversing valve; 321 is a first joystick; 322 is a second joystick; 33 is a travel limit device of the operating mechanism; p1 is a hinge point of the first mechanical arm and the second mechanical arm; p2 is a hinge point of a first operating lever and a second operating lever of the reversing operating mechanism; p31 is the hinge point of the first control rod and the first mechanical arm; p32 is the hinge point of the second control rod and the second mechanical arm;

in the case of the view of figure 3,

110 is an oil tank; 120 is a servo motor; 130 is a hydraulic pump;

in the context of the figure of the drawings,

1 is a hydraulic oil source; 2 is an oil supplementing one-way valve; 31 is a three-position three-way manual servo valve; 41 is a single-acting cylinder; 10 is a first mechanical arm; 20 is a second mechanical arm;

in the context of the illustration of figure 5,

110 is an oil tank; 120 is a servo motor; 130 is a hydraulic pump; 140 is a high pressure accumulator;

in the context of the figure of the drawings,

110 is an oil tank; 120 is a servo motor; 130 is a hydraulic pump; 140 is a high pressure accumulator; 150 is a booster function switch valve;

In the context of the figure of the drawings,

110 is an oil tank; 120 is a servo motor; 130 is a hydraulic pump; 140 is a high pressure accumulator; 150 is a booster function switch valve; 160 is a low-power servo motor; 170 is a low pressure hydraulic pump; 180 is a low pressure accumulator;

in the case of the view of figure 8,

1 is a hydraulic oil source; 2 is an oil supplementing one-way valve; 32 is a three-position four-way manual servo valve; 31 is a three-position three-way manual servo valve; 42 is a double-acting oil cylinder; 41 is a single-acting cylinder; 101 is the mechanical right calf; 201 is the mechanical right thigh; 102 is the mechanical left calf; 202 is the mechanical left thigh; 11 is a right foot pedal; 22 is the left foot pedal; 100 is a back support.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention is suitable for exoskeleton robots, in particular for hydraulic driving and control of heavy-duty (load-bearing) exoskeleton robots, and is suitable for assisting lower limbs, assisting upper limbs and assisting lower limbs or assisting both upper limbs and lower limbs. The invention can be used independently or matched with the conventional technical scheme, namely, the exoskeleton robot driven by hydraulic pressure, part of the mechanical arm joints are driven by the scheme of the invention, and the other part of the mechanical arm joints are driven by the conventional technical scheme.

Example 1

Referring to fig. 1, an embodiment of the present invention applied to an exoskeleton robot for assisting a knee joint is shown. The first mechanical arm (mechanical lower leg A-1) and the second mechanical arm (mechanical upper leg A-2) of the exoskeleton robot are hinged together through a P1 point (note: the first mechanical arm and the second mechanical arm are collectively called as mechanical arms hereinafter, and a more complex hinging manner may be adopted when the mechanical arms are actually designed, but the invention focuses on a hydraulic transmission and a control scheme thereof, and a mechanical structure is only used for expressing design intent). When the exoskeleton robot is worn on a human body, the human body lower leg and the human body thigh are respectively close to the first mechanical arm (mechanical lower leg A-1) and the second mechanical arm (mechanical thigh A-2).

The hydraulic oil pump comprises a hydraulic oil source 1, an oil supplementing one-way valve 2, a manual servo valve 3 and a double-acting oil cylinder 4;

referring to fig. 3, a first embodiment of the hydraulic oil source provided by the present invention is shown. The hydraulic oil source 1 includes an oil tank 110 or a tank actually functioning as an oil tank, a servo motor 120, and a hydraulic pump 130, the servo motor 120 drives the hydraulic pump 130, and the hydraulic pump 130 sucks oil from the oil tank 110 and supplies the oil to an oil inlet of the manual servo valve 3.

The motor can keep the outlet pressure near a certain preset value through regulating the rotating speed and the torque of the motor to form a constant pressure oil source, so that the motor can obtain a faster response speed due to higher standby pressure at the moment of oil supply; the motor can also start to work only when oil supply is needed, and the oil supply flow is adjusted through the adjustment of the rotating speed of the motor. The proposal has the advantages that the motor stops running completely when oil supply is not needed, so the energy consumption is lower; the disadvantage is that the response speed is slow, and the method is not suitable for the working condition requiring high-speed response. For the condition that the motor needs to work in the field for a long time, the motor can be replaced by the motor, and the motor is not a preferable scheme due to the fact that the dead weight of the motor is large.

The manual servo valve 3 can adopt a three-position four-way manual servo valve 32, and is provided with an oil inlet P, an oil return port T and two oil outlets A and B, wherein the port A and the port B are respectively communicated with a rodless cavity and a rod cavity of the double-acting oil cylinder and are respectively communicated with an oil tank through an oil supplementing one-way valve 2;

referring to fig. 2, which is a diagram illustrating the operation principle of the manual servo valve and its mechanical position feedback, the manual servo valve 3 includes a reversing valve 31, a reversing operation mechanism (composed of a first operation lever 321 and a second operation lever 322), and an operation mechanism travel limit device 33. The limiting device is arranged on the exoskeleton robot and used for limiting the maximum travel of the operating rod, namely limiting the maximum deviation of the operating rod and the mechanical arm, and particularly can be in the form of a limiting stop block or a limiting screw and the like.

The first operating rod and the second operating rod of the reversing operating mechanism are hinged together through a P2 point; the first control rod 321 is hinged on the first mechanical arm 10 through a point P31, namely the mechanical calf, and at least one point is tied on the calf of the wearer; the second lever 322 is hinged to the mechanical thigh by point P32 and is attached to the thigh of the wearer at least at one point.

In the initial state of the manual servo valve 3 in the middle position, the hinge point P2 of the first operating lever 321 and the second operating lever 322 is coaxial with the hinge point P1 of the two mechanical arms (i.e. the projection of the point P2 on the mechanical arms coincides with the point P1. Specifically, the schematic diagram in the embodiment is to distinguish the point P1 and the point P2 from the plan view in the principle description, and the two points are intentionally subjected to dislocation treatment). Thus, as the two mechanical arms and the two operating mechanisms rotate around the same axis, as long as the relative positions of the first operating lever 321 and the first mechanical arm 10 and the relative positions of the second operating lever 322 and the second mechanical arm 20 keep unchanged in the initial state, the relative positions of the point P2 and the point P1 are always unchanged in the set rotation angle range no matter how the included angles of the first mechanical arm 10 and the second mechanical arm 20 change, and the reversing valve of the manual servo valve 3 is always in the middle position.

When the wearer makes an action intention, the limbs of the person act before the mechanical arms, which causes the position of the first control rod 321 relative to the first mechanical arm 10 to change, and at the same time, the position of the second control rod 322 relative to the second mechanical arm 20, namely the mechanical thigh also changes, which necessarily causes the hinge points P1 and P2 to deviate, so as to drive the reversing valve to reverse. In the embodiment of fig. 1 and 2, when the human body thigh moves from the leg bending state to the leg extending direction, the valve core is driven to move to the lower right as shown in fig. 1 and 2, the port P is communicated with the port B to supply oil to the rodless cavity of the oil cylinder, and the driving mechanical arm also moves to the leg extending direction and is consistent with the movement direction of the human body thigh, so that the mechanical arm automatically moves along with the human body limb.

Further, the faster the human body stretches the legs, the larger the dislocation quantity of the P1 point and the P2 point is, the larger the opening of the valve port is, the faster the corresponding oil cylinder 4 operates, and the faster the mechanical arm follows the movement of limbs.

In the process that the mechanical arm follows the limb movement of the human body, since the first operating lever 321 and the second operating lever 322 are respectively hinged on the first mechanical arm 10 and the second mechanical arm 20 through the P31 and the P32, the movement of the mechanical arm can change the relative position between the operating lever and the corresponding mechanical arm, and can drive the point P2 to gradually reduce the deviation amount between the point P1 and the point P2. That is, the manual servo valve 3 gradually tends to be closed in the process that the mechanical arm follows the human body limb to gradually approach the state of the mechanical arm to the state of the human body limb. After the mechanical arm moves to the right position along with the limb of the human body, the projections of the P1 and the P2 points are overlapped again, the manual servo valve 3 is reset to the middle position, and the mechanical arm stops moving.

If the human body thigh moves from the straightening state to the leg bending state, the relative position of the mechanical thigh is driven to move towards the leg bending direction until the mechanical thigh moves along with the human body limb in place, and then the movement is stopped. The working principle of the action process is the same as the above, but the working positions of the reversing valves are different, so that the movement directions of the oil cylinders are different, and the relative movement directions of the mechanical arms are different.

When the movement speed of the limbs of the human body is too high, or the hydraulic oil source 1 is closed, and the like, although the manual servo valve 3 is in a reversing state, the mechanical arm cannot follow the limb movement of the human body in time or cannot follow the limb movement of the human body completely, when the displacement of the P2 point exceeds the set range, the P2 point will be limited by the travel limiting device 33 of the operating mechanism, at this time, a wearer can utilize the dead weight of the robot and the exoskeleton robot, or rely on the limb force to forcedly drive the mechanical arm to move through the reversing operating mechanism tied on the human body, the oil inlet of the oil cylinder can absorb oil from the oil tank 110 through the oil supplementing one-way valve 2, and the oil outlet of the oil cylinder can discharge oil to the oil tank through the manual servo valve 3 which is in the reversing state.

In the embodiment of fig. 1, the travel limiting device of the operating mechanism limits the displacement of the point P2, but in implementation, the displacement of other points on the operating mechanism can be limited according to the overall layout requirement or the requirement of ensuring the rigidity of the operating lever, and even limiting devices can be respectively arranged on the first operating lever and the second operating lever.

In order to reduce the discomfort to the wearer caused by excessive impact at the moment the reversing operating mechanism contacts the limiting device 33, the limiting device should be provided with a buffer device, which is not shown in the various embodiments of the present document, but is provided for simplicity and clarity of the schematic illustration.

The relationship between the displacement of the P2 point of the reversing control mechanism and the displacement of the reversing control mechanism and the binding point of the human body relative to the initial position of the reversing control mechanism can be adjusted by changing the installation position or the structural parameters of related parts, including but not limited to adjusting the installation position and the direction of the reversing valve, adjusting the position of the hinging point of the control lever and the mechanical arm, adjusting the position of the binding point of the control lever and the human body limb, and the like. Therefore, under the condition that the state deviation of the human body limbs is the same as that of the mechanical arm, different valve port openings can be obtained, so that a balance point can be conveniently found between the rapid following performance and the motion flexibility of the mechanical arm.

In the various embodiments of the present application listed, the median port cover form of the manual servo valve is preferably a form of approximately zero cover. Due to the objective presence of manufacturing errors, absolute zero coverage cannot be guaranteed, and in particular a small positive coverage or a small negative coverage is possible. The positive covering mode has the advantages that the internal leakage of the middle position is smaller, so that the energy consumption is lower; the disadvantage is that the stability of the cylinder position is slightly poor in the middle position. When a negative cover is used, the advantages are the opposite to those of a positive cover. Further, the reversing valve can be designed as a sliding valve (reversing by utilizing the relative axial movement of the valve sleeve and the valve core) or as a rotary valve (reversing by utilizing the relative rotation of the valve sleeve and the valve core), and the specific forms of reversing operation and mechanical feedback of the reversing valve are correspondingly adjusted.

The manual servo valve and the oil supplementing one-way valve corresponding to the manual servo valve can be arranged in a split mode, but in order to reduce the overall appearance and weight, an integrated design is preferably adopted.

The conventional manual servo valve only has one controlled object, and only can realize that one controlled object moves along with one control input end, and the relative position of the controlled object and the control input end returns to an initial position (corresponding to the manual servo valve being in the middle position) after the controlled object moves along with the control input end in place; the manual servo valve provided by the invention is provided with two controlled objects (a first mechanical arm and a second mechanical arm), the two controlled objects respectively follow the two control input ends (a first control rod and a second control rod) to move, and after the two controlled objects are in place, the relative position of the first mechanical arm and the first control rod is in an initial position (corresponding to the manual servo valve in a middle position), and meanwhile, the relative position of the second control rod and the second mechanical arm is also in an initial position.

In the embodiment of fig. 1 and 2, the manual servo valve has two levers (a first lever and a second lever) connected to each other, and the mechanical arm generates relative movement regardless of which lever is driven. Although the two mechanical arms can be mutually reference objects when moving relatively, the control is different from the first mechanical arm to the second mechanical arm which moves actively. Taking the movement of the knee joint of the human body as an example, there are several cases of the relative movement of the thigh and the calf of the human body: the first case is that the lower leg and the thigh act simultaneously (the included angle between the lower leg and the thigh and the ground change simultaneously); in the second case, the thigh is not moved but only the calf is moved (e.g., the calf is bent backwards when the thigh is upright); the third condition is that the lower leg is not moved but only the thigh is moved (the thigh and the ground angle are changed under the condition that the lower leg and the ground angle are unchanged).

Obviously, when the invention is applied to knee joint assistance, the conventional manual servo valve cannot be used for replacing the knee joint assistance, and the conventional manual servo valve only has one control input end and can only realize the action following of a controlled object. Specific examples are: if the conventional manual servo valve is arranged on the mechanical calf and the control input end of the conventional manual servo valve is tied on the human calf, only the effect that the mechanical calf moves along with the human calf can be obtained, but the movement that the mechanical thigh moves along with the human thigh cannot be realized (the manual servo valve does not have control input when the human calf moves only the thigh).

Further, conventional manual servo valves cannot be used to simply extend the lever attached to the leg of the human body and attach it to the thigh of the human body to obtain a second control input for the thigh of the human body. The reason for this is that: the manual servo valve is provided with two control input ends, the control rod is driven by the human body lower leg to move so that the manual servo valve is changed to move, the mechanical lower leg can move along with the human body lower leg, and the relative position of the first control input end of the control rod and the mechanical lower leg can return to the initial position after the mechanical lower leg is in place, however, the extending end (the other control input end) of the control rod is driven by the human body upper leg to change the manual servo valve, and the relative position of the second control input end and the mechanical upper leg can change along with the change of the included angle of the mechanical upper leg, namely the mechanical upper leg cannot follow the human body upper leg.

The specific structure of the reversing operation of the manual servo valve and its mechanical feedback in the embodiments of fig. 1, 2 and 3 is only one way of achieving the object of the present application, and based on the design concept and working principle of the present application, the structural form thereof may be appropriately changed to obtain the same function, and such appropriate change does not exceed the scope of the present application.

Example 2

Referring to fig. 4, which is a schematic diagram of an embodiment of the present application using a single-acting cylinder to assist knee joints, the difference between the present application and fig. 1 is that the single-acting cylinder 41 is used to assist the knee joints, the manual servo valve 3 may be a three-position three-way manual servo valve 31, and at least one oil inlet, one oil return port, and one oil outlet are provided, the oil outlet is connected to the oil inlet cavity of the single-acting cylinder 41, and the oil outlet is provided with an oil supplementing one-way valve 2 connected to the oil tank 110. Of course, the manual servo valve 3 may also be a three-position four-way servo valve 32 as shown in fig. 1, and one oil outlet is blocked and is equivalent to a three-position three-way manual servo valve, but this is not preferable.

The single-acting oil cylinder is adopted to assist, and the basic working principle of the oil cylinder without a rod cavity is the same as that of the double-acting oil cylinder when the oil cylinder is used for oil feeding. The main difference is that when the oil cylinder is required to retract, the reversing valve reverses to enable the rodless cavity of the single-acting oil cylinder to be communicated with the oil tank, but hydraulic power is not needed to drive the oil cylinder to retract, and the mechanical arm can only be forced to drive the oil cylinder to retract by relying on the dead weight of a human body and an exoskeleton robot or the force of a human body limb.

The double-acting oil cylinder has the advantages of realizing two-way power assistance and small physical consumption of human body, and has the defect of high energy consumption. In view of the fact that in most cases of practical use, the mechanical arm of the exoskeleton robot is only subjected to unidirectional external load (bearing), and the opposite direction movement can be completed by utilizing the dead weights of the human body and the exoskeleton robot (such as squatting actions), or by overcoming the local dead weight and mechanical resistance of the exoskeleton robot by the limb force of the human body (such as non-bearing leg thigh lifting and Qu Xiao leg actions), the local joints or all joints of the exoskeleton robot can adopt single-acting oil cylinders to provide unidirectional assistance according to specific use conditions.

Whether the manual servo valve 3 adopts a three-position four-way valve or a three-position three-way valve, the middle valve port cover mode is preferably close to a zero cover mode, and a small amount of positive cover or a small amount of negative cover can be adopted according to actual use requirements.

Example 3

Referring to fig. 5, a second embodiment of the hydraulic oil source of the present invention is shown, which differs from fig. 3 only in that the outlet of the hydraulic pump 130 is connected to the high pressure accumulator 140 for maintaining pressure through a check valve. The hydraulic transmission exoskeleton robot with high response speed is characterized in that a hydraulic oil source is preferably a constant pressure oil source, and a high-pressure accumulator is arranged, so that the instantaneous maximum oil supply flow is improved, and the high-pressure accumulator can play a role in buffering.

Example 4

Referring to fig. 6, a third embodiment of the hydraulic oil source of the present invention is shown, which differs from fig. 3 and 5 only in that a booster function switching valve 150 is added before the manual servo valve. The technical scheme is applicable to both single-acting oil cylinders and double-acting oil cylinders. The manual servo valves are arranged on the left leg knee joint driving oil cylinder and the left leg hip joint driving oil cylinder, the right leg knee joint driving oil cylinder and the right leg hip joint driving oil cylinder are arranged in groups, and the manual servo valves corresponding to the oil inlet paths of the groups of oil cylinders share one power assisting function switching valve.

The boost function switch valve 150 can be manually forced to open or close, for example, if the wearer has other auxiliary measures to ensure the body balance maintaining ability (such as holding a crutch) in case of excessive physical exertion, the boost function can be forced to open without being limited by preset conditions of the boost function switch; when the power assisting function is forcibly closed or the power assisting function is lost because the energy consumption of the battery is finished, the mechanical arm can be forcibly driven to move under the combined action of the manual servo valve, the oil supplementing one-way valve and the operating mechanism limiting device, and the limbs of a person can still normally move.

The power-assisted function switching valve can be opened and closed, the actual stress of a human body can be detected by installing a force sensor at a proper position, and then the power-assisted function is automatically determined to be opened or not after the power-assisted function is compared with a preset value, namely, when the actual stress of the human body is larger than or equal to a first preset value, the power-assisted function of a corresponding joint is automatically opened, and when the actual stress of the human body is smaller than or equal to a second preset value, the power-assisted function of the corresponding joint is closed. The first preset value and the second preset value may be equal or unequal, but unequal schemes are preferred. This function is a very practical function, the practicality including:

1) The energy consumption is reduced, the battery endurance is improved, and the heating value of the system is reduced.

In order to increase the response speed, a constant pressure oil source is generally adopted for driving, and the standby pressure of the constant pressure oil source is equal to or slightly higher than the minimum oil supply pressure required by the oil cylinder. Thus, when the load is lighter (such as when the non-bearing leg is lifted and stretched), the hydraulic transmission efficiency is lower and the ineffective energy consumption is larger. At this time, if the local assistance is turned off, the energy consumption can be greatly reduced.

2) The operation efficiency is improved under the condition of not increasing the energy consumption.

Because the scheme of the invention has the function that the human body can override to drive the mechanical arm to move freely, when the actual movement speed of the human body exceeds the maximum speed allowed by the instantaneous maximum flow, even if the power assisting function is started, the power assisting effect is poor, but larger energy can be wasted, and at the moment, the local power assisting function is necessary to be closed. When the load is lighter, the power assisting function is closed, the movement speed of the human body is not limited by the instantaneous maximum oil supply flow, and the energy consumption is not increased while the higher speed is obtained.

3) Based on the function of turning on or off local assistance, the characteristic can be used for adjusting the sharing proportion of the human body and the machine to external load, namely adjusting the assistance ratio, so as to give consideration to the assistance effect and the capability of keeping balance of the human body, and make the human-machine coordinate work. When the scheme of the invention is applied to upper limb assistance, the machine can be selected to bear all or most of external load so as to reduce the physical consumption of people. However, when assisting the lower limbs of the human body, the human body should bear external load (load) in a proper proportion so as to sense the change of the gravity center of the external load and adjust the posture of the human body in time to adapt to the change, thereby avoiding suddenly losing balance.

In order to realize the assistance ratio adjustable function, a force sensor is added at a proper position according to different assistance joints in the specific implementation, the actual stress of a human body is detected, and the actual stress is compared with a preset value to determine the opening or closing of the assistance function. For example, when the lower limb is assisted, a force sensor can be arranged on the sole, when the actual stress of the sole of a person is detected to be more than or equal to a first preset value, the assistance function is automatically started, and when the actual stress of the sole of the person is less than or equal to a second preset value, the assistance function is automatically closed. Thus, the actual force applied by the human can be kept within a certain set range, and thus the assistance effect and the body balance keeping capability can be simultaneously achieved.

The mounting position of the force sensor is determined according to the specific assistance of which joint and the different stress conditions of the limbs under different movement postures. A force sensor can be installed at one or more positions, and the opening or closing of the power assisting function switching valve can be determined through simple logic comparison. For example, in an exoskeleton robot for assisting lower limbs, if a kneeling state is required in work, besides installing a force sensor on the sole of a foot, a human knee kneeling pad is arranged at a knee joint of a mechanical arm, and a force sensor is arranged on the kneeling pad.

Example 5

Referring to fig. 7, which is a schematic diagram of a fourth embodiment of the hydraulic oil source according to the present invention, the hydraulic oil source differs from fig. 3, 5 and 5 only in that a low-pressure oil source (which may share an oil tank with a high-pressure oil source) is additionally configured, a low-power motor 160 is added to drive another low-pressure hydraulic pump 170, a low-pressure accumulator 180 is installed at the outlet of the low-pressure hydraulic pump 170, the outlet pressure of the low-pressure hydraulic pump 170 is maintained at a low level through the rotation speed and torque control of the low-power motor 160, and the oil outlet of the low-pressure hydraulic pump 170 supplies oil to the outlet of the booster function switching valve 150 through a check valve.

The technical scheme that the exoskeleton robot controls the working state of the power-assisted function switching valve according to the actual stress of the human body disclosed by the embodiment 4 of the invention can automatically close the power-assisted function of the corresponding joint when the local limb is in a light-load state, and then the mechanical arm is driven by manpower to move can meet most of the use conditions, but for the relatively heavy exoskeleton robot with higher load capacity requirement, when the double-acting oil cylinder is adopted for power assistance, the resistance to be overcome by the human body after the power-assisted function is closed is larger, and the human body burden is heavier. In this embodiment, the auxiliary oil supply of the low-pressure oil source is added on the basis of embodiment 4, so that the inlet of the manual servo valve 3 is supplied with oil by the low-pressure oil source under the condition that the power assisting function switching valve 150 is closed, so as to overcome the local dead weight and mechanical resistance and reduce the burden of a human body. Meanwhile, the pressure of the low-pressure oil source is close to the use pressure in the light-load state, so that the energy consumption is low, and the total energy consumption is low because the working pressure is low.

Example 6

Referring to fig. 7, a complete embodiment of the lower limb assistance of the present invention is shown, in the foregoing embodiments, the configurations of the cylinder, the manual servo valve, the hydraulic oil source, etc. may have two or more choices according to the actual use requirements, and these choices may be applied in combination when the present invention is applied to assistance of multiple joints. For the purpose of illustrating this invention, the embodiment of fig. 8 is used.

In the embodiment of fig. 8, a single-acting cylinder 41 is adopted for each of the left knee joint and the right knee joint to provide unidirectional power assistance, and a three-position three-way manual servo valve 31 is adopted for the manual servo valve 3; the left hip joint and the right hip joint respectively adopt a double-acting oil cylinder 42 to provide two-way assistance, and the manual servo valve used adopts a three-position four-way manual servo valve 32; the oil cylinders 4 of all joints share the hydraulic oil source 1, share the high-pressure oil source and also share the low-pressure oil source, and the high-pressure oil source and the low-pressure oil source share one oil tank 110; the high-pressure oil source is provided with a high-pressure accumulator 140, and the low-pressure oil source is provided with a low-pressure accumulator 180 so as to improve the response speed of the mechanical arm; the left leg knee joint cylinder and the left leg hip joint cylinder are a group, wherein the left leg knee joint is connected with the mechanical left lower leg 102 and the mechanical left thigh 202, and the left leg hip joint is connected with the mechanical left thigh 202 and the back bracket 100; the right leg knee cylinder and the right leg hip cylinder are a group, wherein the right leg knee connects the mechanical right calf 101 and the mechanical right thigh 201, and the right leg hip connects the mechanical right thigh 201 and the back support 100. The two groups of cylinders are respectively provided with a power assisting function switch valve 150; the force sensors are installed on the right pedal 11 and the left pedal 22, and the power assisting function switch valve 150 is opened or closed by comparing the actual force of the collected sole with a preset value: the sole stress is larger than or equal to a first preset value, the boosting function is started, and the boosting function is closed when the sole stress is smaller than or equal to a second preset value; the booster function switching valve 150 may be opened or closed by override of the wearer.

With regard to the principle of action and the effect of the embodiment of fig. 8, reference is made to the description hereinbefore.

It should be noted that the embodiment of fig. 8 is a combination of the lower limb assistance of the exoskeleton robot according to the present invention, and the application of the present invention is not limited to this combination.

According to the characteristics of the body limb movement, when the invention is applied to certain joint assistance, if only one of the mechanical arms hinged with each other needs to actively move, the manual servo valve can only have one control input end. For example, when the shoulder joint of the human body is assisted, the large arm is usually driven to move relative to the human body, the large arm is not required to be fixed, the human body is driven to move relative to the large arm, and the manual servo valve is allowed to have only one control input end tied on the large arm of the human body. The manual servo valve used may be a manual servo valve of the present invention, but the first lever or the second lever is omitted, or a conventional manual servo valve may be used instead.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A valve controlled hydraulic transmission system for an exoskeleton robot, comprising: the hydraulic oil source, the manual servo valve, the oil supplementing one-way valve, the oil cylinder and the mechanical arm;

the relative position of the control rod and the mechanical arm generates deviation from an initial state, the deviation drives the reversing valve to reverse, the direction of the deviation determines the reversing direction of the reversing valve, and the magnitude of the deviation is positively related to the opening of the valve port of the reversing valve.

2. The valve controlled hydraulic transmission system for an exoskeleton robot of claim 1, wherein said reversing lever comprises a first lever and a second lever connected to each other, said robot arm comprising a first robot arm, a second robot arm hinged to said first robot arm; the first control rod is directly or indirectly connected with the first mechanical arm at least at one point, the second control rod is directly or indirectly connected with the second mechanical arm at least at one point, and when the relative position of the first control rod and the first mechanical arm and the relative position of the second control rod and the second mechanical arm are in an initial state, the reversing valve of the manual servo valve is in a middle position;

3. The valve-controlled hydraulic transmission system applied to the exoskeleton robot according to claim 2, wherein when the first mechanical arm does not act, the deviation generated between the relative position of the second control lever and the second mechanical arm and the initial state drives the reversing valve to reverse; or when the second mechanical arm does not act, the deviation generated between the relative position of the first control lever and the first mechanical arm and the initial state drives the reversing valve to reverse.

4. The valve controlled hydraulic transmission system for an exoskeleton robot of claim 1, wherein the cylinder is a single-acting cylinder or a double-acting cylinder.

5. The valve-controlled hydraulic transmission system applied to the exoskeleton robot of claim 4, wherein the manual servo valve is a three-position four-way manual servo valve and is provided with two oil outlets, and the two oil outlets are respectively communicated with a rodless cavity and a rod cavity of the double-acting oil cylinder; or one of the oil outlets is communicated with an oil inlet cavity of the single-acting oil cylinder.

6. The valve controlled hydraulic transmission system for an exoskeleton robot of claim 4, wherein said manual servo valve is a three-position three-way manual servo valve having an oil outlet, and said oil outlet is in communication with an oil inlet chamber of said single-acting cylinder.

7. A valve controlled hydraulic transmission system for an exoskeleton robot as claimed in claim 1, wherein the outlet of the hydraulic pump is connected to the high pressure accumulator via a one-way valve.

8. A valve-controlled hydraulic transmission system applied to an exoskeleton robot according to claim 1 or 7, wherein a booster function switching valve is arranged on an oil inlet path of the manual servo valves, wherein each manual servo valve is provided with one booster function switching valve or groups a plurality of manual servo valves, each group of manual servo valve oil inlet paths share one booster function switching valve, and the control mode of the booster function switching valve comprises forced opening or closing of the booster function switching valve by a wearer.

9. The valve-controlled hydraulic transmission system for an exoskeleton robot of claim 8, wherein said hydraulic oil source further comprises a low pressure oil source for supplying oil to the oil outlet of said booster function switching valve via a check valve.

10. The valve-controlled hydraulic transmission system for an exoskeleton robot of claim 8, further comprising a force sensor for detecting an actual force applied to a body limb, and comparing the detected force with a preset value to determine a working position of the power-assisted function switching valve, wherein the power-assisted function switching valve is closed when the actual force applied to the body limb is less than or equal to a first preset value, and the power-assisted function switching valve is opened when the actual force applied to the body limb is greater than or equal to a second preset value.