CN102440854B - Human-machine coupling overload carrying system device and control method thereof - Google Patents

Abstract

The invention relates to a human-machine coupling overload carrying system device and a control method thereof, which is characterized in that pressure sensors and angle sensors are mounted under the feet of a human body and at the knee joints of rigid limbs of an overload carrying system respectively, so as to perceive movement information and force information of the human body and the rigid limbs of the overload carrying system real-timely, and then real-time and accurate information can be provided for human-machine coupling control; through adoption of a human-machine coupling smart control method, different control algorithms are adopted according to different gaits, position feedback control and force feedback control are performed to an executive device, and the movement information and the force information of the human body, which are perceived by the sensors, are transformed into control parameters through filtering and fusion, so that a control actuator can output a proper force real-timely in a follow-up manner, tracks the human body movement and provides an efficient and proper assisting force for the human body movement real-timely; through adoption of a gas energy storage airtight cavity actuator device, the assisting effect of hydraulic cylinder return movement can be achieved, so that flexibility and comfortableness of human-machine coupling movement are improved.

Description

A kind of human-machine coupling overload carrying system device and control method thereof

Technical field

The present invention relates to a kind of carrying system device and control method thereof, particularly about a kind of human-machine coupling overload carrying system device and control method thereof.

Background technology

In trekking in way far away, the equipment that people self need to carry and goods and materials are more and more, can affect like this people's gait of march, travel distance and maneuverability, usually make people's neurolysis or bodily injury.When adopting traditional Robot Control Technology to carry out human body Carrying load motion power-assisted, portable force aid system is difficult to meet real-time, accuracy and the man-machine coordination campaign compliance under human body loading condition, controlled, particularly under fully loaded transportation condition, when human body walk fast, run, during across Tiao Deng strenuous exercise, the device that these are traditional and control method thereof can cause certain obstruction to people's motion, affect motion concertedness.

Summary of the invention

For the problems referred to above, the object of this invention is to provide a kind of human-machine coupling overload carrying system device and control method thereof of real-time, accuracy and the man-machine coordination campaign compliance that can promote the control of overload carrying system senses.

Realize above-mentioned purpose, the present invention takes following technical scheme: a kind of device of human-machine coupling overload carrying system, it comprises the firm limbs of coupling corresponding to human body lower extremity, just limbs comprise two groups of shank parts and thigh part, be connected to two knee joints and executor between shank part and thigh part, be connected to two sensing boots of shank part bottom, be arranged on two thigh part tops and be positioned at the backrest of human body back, and control system and power supply; It is characterized in that: each executor comprises a hydraulic cylinder, hydraulic cylinder is connected to the middle part of thigh part, and connects successively servo valve, electro-hydraulic reversing valve, fuel tank and oil pump by oil pipe, and fuel tank and oil pump are arranged on backrest bottom; The piston rod of hydraulic cylinder connects the middle part of shank part, and the inner of piston rod is provided with a circle hydraulic cylinder is separated into the flange in a hydraulic cavities and a gas energy storage chamber; Control system comprises two groups of plantar pressure sensor that are arranged in two sensing boots, be arranged on the two knee joint angle sensors at two knee joint places, be arranged on the gait judge module in Control card in backrest, actuator position computing module, controller module, amplifier module, hydraulic regulation module, executor's equivalent modules, support heavy burden compensating module and two adders; Gait judge module by the plantar pressure sensor signal obtaining and in it preset given threshold value compare and judge; The piston rod position Y that the knee joint angle changing value θ that actuator position computing module is exported the knee joint sensor obtaining and Qi Nei are preset and the relational expression of knee joint angle changing value θ, calculate piston rod position Y; Controller module is by the mathematical model expression formula G of PID controller preset in it _pID, the deviate being obtained is converted to voltage control signal U _ctrl, and output it to amplifier module; Amplifier module is by preset relational expression K in it _aby the voltage control signal U of input _ctrlbe converted to servo current amount I, and output it to hydraulic regulation module; Hydraulic regulation module is by preset relational expression G in it _svthe servo current amount I of input is converted to the aperture size x of servo valve valve _v, and outputing it to executor's equivalent modules, executor's equivalent modules is by preset equivalent mathematical model expression formula G in it _eq, by the aperture size x of servo valve valve _vwith the support heavy burden balancing force F that supports heavy burden compensating module and feed back _comp, be converted to the position Y that piston rod should be exported _need, support heavy burden compensating module by its inner preset equivalent mathematical model G _compthe position Y that piston rod should be exported _needbe converted to the support heavy burden balancing force F that piston rod should be exported _comp, and it is fed back to executor's equivalent modules again.

Described in one group, plantar pressure sensor is two, is placed on respectively the position contacting with rear heel with human body forefoot, plantar pressure sensor output voltage signal.

The mathematical model expression formula G of preset PID controller in described controller module _pIDfor:

G _PID＝K _P+T _Ds+T _I/s

In formula: K _pfor proportionality coefficient, T _dfor differential coefficient, T _ifor integral coefficient.

The mathematical model expression formula G of preset PID controller in described controller module _pIDfor:

G _PID＝K _P+T _Ds+T _I/s

In formula: K _pfor proportionality coefficient, T _dfor differential coefficient, T _ifor integral coefficient.

The interior preset piston rod position Y of described actuator position computing module and the relational expression of knee joint angle changing value θ are:

$Y=\sqrt{{\mathrm{Dist}1}^2+{\mathrm{Dist}2}^2-2\×\mathrm{Dist}1\×\mathrm{Dist}2\×\cos ({\mathrm{\θ}}_{\mathrm{init}}-\mathrm{\θ})}$

In formula: θ _initbe static kneed initial angle value when upright of human body, Dist1 is that the junction point of hydraulic cylinder on thigh part is to the distance between knee joint; Dist2 is that the junction point of hydraulic cylinder on shank part is to the distance between knee joint;

Preset relational expression K in amplifier module _afor:

$K_a=\frac{I}{U_{\mathrm{ctrl}}}$

In formula: K _ait is a gain amplifier constant;

Preset relational expression G in hydraulic regulation module _svfor:

$G_{\mathrm{sv}}=\frac{x_v}{I}=\frac{K_{\mathrm{sv}}}{\frac{s^2}{{{\mathrm{\ω}}_{\mathrm{sv}}}^2}+\frac{{2\mathrm{\ξ}}_{\mathrm{sv}}}{{\mathrm{\ω}}_{\mathrm{sv}}}s+1}$

In formula: ω _svthe natural frequency of servo valve, ξ _svthe damping ratio of servo valve, K _svit is the gain constant of servo valve;

Preset equivalent mathematical model G in executor's equivalent modules _eqfor:

$G_{\mathrm{eq}}=\frac{\frac{K_q}{A_p}}{\frac{V_t{m}_t}{{4\mathrm{\β}}_e{A}_p^2}{s}^3+(\frac{m_t{K}_{\mathrm{ce}}}{A_p^2}+\frac{B_e{V}_t}{{4\mathrm{\β}}_e{A}_p^2})s^2+(1+\frac{B_e{K}_{\mathrm{ce}}}{A_p^2}+\frac{{\mathrm{KK}}_{\mathrm{ce}}}{A_p^2})s+\frac{{\mathrm{KK}}_{\mathrm{ce}}}{A_p^2}}$

In formula: m _tthe quality of the shank part of firm limbs, B _ethe damping of firm limbs, β _ethe hydraulic oil elastic modelling quantity in hydraulic cylinder, K _cebe the total flow-pressure coefficient of servo valve, K is the spring rate of firm limbs, K _qthe flow gain of servo valve, A _pthe effective area of piston rod, V _tit is the total measurement (volume) of hydraulic cylinder;

Support preset equivalent mathematical model G in heavy burden compensating module _compfor:

G _comp＝G _YtoFG _FtoFK

Wherein,

$G_{\mathrm{FtoFK}}=\frac{1}{K_q{A}_p}(K_{\mathrm{ce}}+\frac{V_t}{{4\mathrm{\β}}_e}s)$

$G_{\mathrm{YtoF}}=\frac{F_{\mathrm{comp}}}{Y_{\mathrm{need}}}.$

The gait obtaining according to described gait judge module is chosen G in following scope _ytoFvalue:

0≤G _YtoF≤1866

Wherein, when when single lower limb walking swings, G _ytoF=0;

The control method of above-mentioned a kind of human-machine coupling overload carrying system, comprise the following steps: 1) on the thigh part of the firm limbs of human-machine coupling overload carrying system, a hydraulic cylinder is set, the piston rod of hydraulic cylinder is connected on the shank part of firm limbs, a circle flange is set in the inner of piston rod hydraulic cylinder is separated into a hydraulic cavities and a gas energy storage chamber; Simultaneously, plantar pressure sensor and the knee joint angle sensor corresponding with human body are set in the control system of firm limbs, and are arranged on gait judge module, actuator position computing module, controller module, amplifier module, hydraulic regulation module, executor's equivalent modules, support heavy burden compensating module and two adders on a Control card; 2) plantar pressure sensor gathers plantar pressure information, knee joint angle sensor acquisition knee joint rotation angle information; 3) gait judge module by the plantar pressure sensor signal obtaining and in it preset given threshold value compare and judge, and according to judged result, select one of following three kinds of control instructions to carry out:

1. when when single lower limb walking is supported, executing location closed loop control and power closed loop control instruction, enter step 4);

2. when in both legs stationary support, executing location closed loop control instruction, enters step 5);

3. when when single lower limb walking swings, carry out gradual change open loop control instruction, enter step 6);

4) actuator position computing module is according to the knee joint angle expectancy changes value θ of the knee joint angle sensor output obtaining _exprelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod desired locations Y _exp, and export to adder; Actuator position computing module is according to the knee joint angle actual change value θ of the knee joint angle sensor output obtaining _sensorrelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod physical location Y _act, and export to adder; Adder is by the desired locations Y of the piston rod obtaining _expwith physical location Y _actsubtract each other, and the deviate calculating is exported to controller module; Another adder is subtracted each other the plantar pressure sensor signal obtaining and the vola expected signal value being preset in control system, and the deviate calculating is exported to controller module; Controller module is according to the desired locations Y of the piston rod obtaining _expwith physical location Y _actdeviate, and the deviation of plantar pressure sensor signal and vola expected signal value, and the mathematical model expression formula G of preset PID controller in it _pID, calculate voltage control signal U _ctrl, and output it to amplifier module, enter step 7); 5) by piston rod desired locations Y _expmaximum Y for people's executor's piston rod outgoing position when the both legs stationary support state is set _maxand export to adder; Actuator position computing module is according to the knee joint angle actual change value θ of the knee joint angle sensor output obtaining _sensorrelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod physical location Y _act, and export to adder; Adder is by the desired locations Y of the piston rod obtaining _expwith physical location Y _actsubtract each other, and the deviate calculating is exported to controller module; Controller module is according to the desired locations Y of the piston rod obtaining _expwith physical location Y _actdeviate and the mathematical model expression formula G of the preset PID controller of Qi Nei _pID, calculate voltage control signal U _ctrl, and output it to amplifier module, enter step 7); 6) actuator position computing module is according to the knee joint angle expectancy changes value θ of the knee joint angle sensor output obtaining _exprelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod desired locations Y _exp, and export to adder; Adder is by the desired locations Y of the piston rod obtaining _expdirectly export to controller module; Controller module is according to the desired locations Y of the piston rod obtaining _exp, and the mathematical model expression formula G of its interior preset PID controller _pID, calculate voltage control signal U _ctrl, and output it to amplifier module; 7) amplifier module is by preset relational expression K in it _aby the voltage control signal U obtaining _ctrlbe converted to servo current amount I, and output it to hydraulic regulation module; 8) hydraulic regulation module is by preset relational expression G in it _svthe servo current amount I obtaining is converted to the aperture size x of servo valve valve _v, and output it to executor's equivalent modules; 9) executor's equivalent modules is by preset equivalent mathematical model expression formula G in it _eq, by the aperture size x of the servo valve valve obtaining _vwith the support heavy burden balancing force F that supports heavy burden compensating module and feed back _compbe converted to the position Y that piston rod should be exported _need, and output it to support heavy burden compensating module; 10) support heavy burden compensating module by its inner preset equivalent mathematical model G _compthe position Y that piston rod should be exported _needbe converted to the support heavy burden balancing force F that piston rod should be exported _comp, and it is fed back to executor's equivalent modules again, and return to step 2), until control system is sent order fulfillment circulation.

Described step 4) in, support force F is expected in the vola desired signal and the preassigned vola that are preset in control system _expcorrespondence, support force F is expected in described vola _expfor bearing a heavy burden after deduction body weight and overload carrying system device deadweight weight sum.

The present invention is owing to taking above technical scheme, it has the following advantages: 1, the present invention is owing on overload carrying system sensing boots and the just knee joint place of limbs laying respectively pressure transducer and angular transducer, the knee joint angle information of real-time perception Human Sole pressure information and just limbs, thereby for man-machine coupling control system provides in real time, information accurately.2, the present invention is owing to adopting coupled intelligent control method, according to different gaits, adopt different control algolithms, actuating unit is carried out to position feedback control and force feedback control, thus can real-time tracking human motion and provide efficient suitable power-assisted for human motion.3, the present invention, due to the hydraulic cylinder actuator apparatus adopting with gas energy storage chamber, has realized the power-assisted effect of hydraulic cylinder executor quick return, thereby has promoted compliance and the comfortableness of coupled motion.

Accompanying drawing explanation

Fig. 1 is overload carrying system schematic of the present invention

Fig. 2 is executor's schematic diagram of the present invention

Fig. 3 is control system operation principle schematic diagram of the present invention

Fig. 4 is control program schematic diagram of the present invention

Fig. 5 is that plantar pressure sensor of the present invention arranges schematic diagram

Fig. 6 is that the angle that knee joint sensor of the present invention obtains changes schematic diagram

The specific embodiment

Below in conjunction with accompanying drawing, embodiments of the present invention are described in detail.

As shown in Figure 1, the present invention is same as the prior art, comprise the firm limbs of coupling corresponding to human body lower extremity, these firm limbs comprise two groups of shank parts 1 and thigh part 2, be connected to two knee joints 3 and executor 4 between shank part 1 and thigh part 2, be connected to two sensing boots 5 of shank part 1 bottom, be arranged on two thigh part 2 tops and be positioned at the backrest 6 of human body back, and control system 7 and power supply 8.

As shown in Figure 2, executor 4 of the present invention comprises a hydraulic cylinder 41, one end of hydraulic cylinder 41 is connected to the middle part of thigh part 2, and this end is provided with an ozzle 42, ozzle 42 connects a servo valve 43, an electro-hydraulic reversing valve 44, a fuel tank and oil pump 45 by oil pipe, and fuel tank and oil pump 45 are arranged on backrest 6 bottoms.The other end of hydraulic cylinder 41 is inserted with a piston rod 46, and the inner of piston rod 46 is provided with a circle flange 47, and hydraulic cylinder 41 is separated into a hydraulic cavities 48 and a gas energy storage chamber 49, and the outer end of piston rod 46 is connected to the middle part of shank part 1.

As shown in Figure 3, Figure 4, control system 7 of the present invention comprises four plantar pressure sensor 71, two knee joint angle sensors 72, be arranged on a gait judge module in Control card 73, actuator position computing module 74, controller module 75, amplifier module 76, hydraulic regulation module 77, executor's equivalent modules 78, one support heavy burden compensating module 79 and two adders, Control card is arranged on backrest 6 bottoms.

As shown in Figure 5, four plantar pressure sensor 71 in control system 7 are divided into two groups, and 71, two plantar pressure sensor 71 of every group of two plantar pressure sensor are placed on respectively the position contacting with rear heel with human body forefoot in sensing boots 5.Four plantar pressure sensor 71 are sent the magnitude of voltage recording into gait judge module 73, preset given voltage threshold in gait judge module 73, and this voltage threshold can be set according to the sensitivity of sensor and experiment experience.By gait judge module 73, judge the gait situation that human body is current: when the output valve sum of each group in two groups of plantar pressure sensor 71 is all greater than given voltage threshold, show in " both legs stationary support " state; When only wherein the output valve sum of one group of pressure transducer is greater than given voltage threshold, show that this lower limb is in " single lower limb walking is supported " state; And another lower limb is in " single lower limb walking swings " state (as shown in Figure 4).

As shown in Figure 1, Figure 3, two knee joint angle sensors 72 of control system 7 are arranged on two knee joint 3 places, and two knee joint sensors 72 are exported to actuator position computing module 74 by the knee joint angle changing value θ recording.The relational expression that presets piston rod 46 current location Y and knee joint angle changing value θ in actuator position computing module 74, this relational expression is as follows:

$Y=\sqrt{{\mathrm{Dist}1}^2+{\mathrm{Dist}2}^2-2\×\mathrm{Dist}1\×\mathrm{Dist}2\×\cos ({\mathrm{\θ}}_{\mathrm{init}}-\mathrm{\θ})}$

In formula: θ _initbe the static initial angle value of knee joint 3 when upright of human body, Dist1 is that the junction point of hydraulic cylinder 21 on thigh part 2 is to the distance between knee joint 3; Dist2 is that the junction point of hydraulic cylinder 21 on shank part 1 is to the distance (as shown in Figure 6) between knee joint 3.When human body is during in upright situation, knee joint angle sensor 72 output angle changing value θ are zero; When shank part 1 is bending backward, angle changing value θ be made as on the occasion of; When shank part 1 stretches forward, angle changing value θ is made as negative value.Actuator position computing module 74 can calculate piston rod position Y according to known knee joint angle changing value θ, otherwise, also can extrapolate knee joint angle changing value θ according to known piston rod position Y.

As shown in Figure 3, in the controller module 75 of control system 7, preset the mathematical model expression formula G of a second order PID controller _pID:

G _PID＝K _P+T _Ds+T _I/s

Controller module 75 can be according to the difference of the different of gait and the requirement (as stability, tracking accuracy and rapidity etc.) to systematic function, to the Proportional coefficient K in above formula _p, differential coefficient T _dwith integral coefficient T _ideng control parameter, choose different values.The function of controller module 75 is that the departure obtaining is converted into a voltage control signal U _ctrl, and export to amplifier module 76.Controller mathematical model that also can preset other form in controller module 75.

As shown in Figure 3, in the amplifier module 76 of control system 7, preset the voltage control signal U that a controller module 75 provides _ctrlrelational expression K with servo current amount I _a:

$K_a=\frac{I}{U_{\mathrm{ctrl}}}$

K _abe a gain amplifier constant, its size can be set according to system requirements.The function of amplifier module 76 is voltage control signal U that controller module 75 is provided _ctrlbe converted to servo current amount I, and servo current amount I is exported to hydraulic regulation module 77.

As shown in Figure 3, in the hydraulic regulation module 77 of control system 7, preset the aperture size x of a servo current amount I and servo valve 43 valves _vrelational expression G _sv:

$G_{\mathrm{sv}}=\frac{x_v}{I}=\frac{K_{\mathrm{sv}}}{\frac{s^2}{{{\mathrm{\ω}}_{\mathrm{sv}}}^2}+\frac{{2\mathrm{\ξ}}_{\mathrm{sv}}}{{\mathrm{\ω}}_{\mathrm{sv}}}s+1}$

In formula: ω _svthe natural frequency of servo valve 43, ξ _svthe damping ratio of servo valve 43, K _svthe gain constant of servo valve 43, K _svvalue by the performance parameter of servo valve 43, determined.The function of hydraulic regulation module 77 is aperture size x that servo current amount I that amplifier module 76 is provided is converted to servo valve 43 valves _vthereby, regulate the flow that enters hydraulic oil in hydraulic cavities 48.

Under the effect that enters hydraulic oil in hydraulic cavities 48, overcome heavy burden restraining forces moves to the position that arrive to piston rod 46 in executor 4 of the present invention exactly, thus real-time tracking human motion provide efficient suitable power-assisted for human motion.With reference to the technical data about position feedback control system principle in < < hydraulic control system > >, executor 4 of the present invention adopts following mathematical model formulate:

$Y_{\mathrm{need}}=\frac{\frac{K_q}{A_p}{x}_v-\frac{1}{A_p^2}(K_{\mathrm{ce}}+\frac{V_t}{{4\mathrm{\&beta;}}_e}s)F_{\mathrm{comp}}}{\frac{V_t{m}_t}{{4\mathrm{\&beta;}}_e{A}_p^2}{s}^3+(\frac{m_t{K}_{\mathrm{ce}}}{A_p^2}+\frac{B_e{V}_t}{{4\mathrm{\&beta;}}_e{A}_p^2})s^2+(1+\frac{B_e{K}_{\mathrm{ce}}}{A_p^2}+\frac{{\mathrm{KK}}_{\mathrm{ce}}}{A_p^2})s+\frac{{\mathrm{KK}}_{\mathrm{ce}}}{A_p^2}}$

In formula: F _compto support heavy burden balancing force, Y _needthe position that piston rod 46 should be exported, m _tthe quality of the shank part 1 of firm limbs, B _ethe damping of firm limbs, β _ethe hydraulic oil elastic modelling quantity in hydraulic cylinder 41, K _cebe the total flow-pressure coefficient of servo valve 43, K is the spring rate of firm limbs, K _qthe flow gain of servo valve 43, A _pthe effective area of piston rod 46, V _tit is the total measurement (volume) of hydraulic cylinder 41.Above formula also can be equivalent to:

Y _need＝(x _v-Y _needG _YtoFG _FtoFK)×G _eq

Wherein,

$G_{\mathrm{eq}}=\frac{\frac{K_q}{A_p}}{\frac{V_t{m}_t}{{4\mathrm{\&beta;}}_e{A}_p^2}{s}^3+(\frac{m_t{K}_{\mathrm{ce}}}{A_p^2}+\frac{B_e{V}_t}{{4\mathrm{\&beta;}}_e{A}_p^2})s^2+(1+\frac{B_e{K}_{\mathrm{ce}}}{A_p^2}+\frac{{\mathrm{KK}}_{\mathrm{ce}}}{A_p^2})s+\frac{{\mathrm{KK}}_{\mathrm{ce}}}{A_p^2}}$

$G_{\mathrm{FtoFK}}=\frac{1}{K_q{A}_p}(K_{\mathrm{ce}}+\frac{V_t}{{4\mathrm{\&beta;}}_e}s)$

$G_{\mathrm{YtoF}}=\frac{F_{\mathrm{comp}}}{Y_{\mathrm{need}}}$

As shown in Figure 3, in the executor's equivalent modules 78 in control system 7, preset above-mentioned equivalent mathematical model G _eq.The function of executor's equivalent modules 78 is aperture size x of servo valve 43 valves that hydraulic regulation module 77 is provided _vwith the support heavy burden balancing force F that supports heavy burden compensating module 79 and provide _comp, be converted to the position Y that in executor 4, piston rod 46 should be exported _needthereby the piston rod 46 of controlling in executor 4 moves to the position that arrive.

As shown in Figure 3, in the support heavy burden compensating module 79 in control system 7, preset an equivalent mathematical model G _comp:

G _comp＝G _YtoFG _FtoFK

In above formula, according to different gaits, G _ytoFvalue also different, according to experiment test, obtain G _ytoFspan be generally:

0≤G _YtoF≤1866

When single lower limb walking swings, G _ytoF=0.

The function that supports heavy burden compensating module 79 is the position Y that should export according to the current piston rod obtaining 46 _needcalculate the support heavy burden balancing force F that current piston rod 46 should be exported _comp, and output feeds back to executor's equivalent modules 78.

The open-loop transfer function G of whole control system 7 _openbe:

$G_{\mathrm{open}}=\frac{G_{\mathrm{PID}}{K}_a{G}_{\mathrm{sv}}{G}_{\mathrm{eq}}}{(1+G_{\mathrm{hyd}\_\mathrm{eq}}{G}_{\mathrm{YtoF}}{G}_{\mathrm{FtoFK}})}$

As shown in Figure 4, power supply 8 of the present invention is arranged on backrest 6 bottoms, power supply 8 can adopt lithium battery device, by lithium battery, is that the power devices such as plantar pressure sensor 71, knee joint angle sensor 72, control system 7 and servo valve 43 and oil pump are powered.

As shown in Figure 3, the operation principle of control system 7 is as follows:

During human motion, knee joint produces the anglec of rotation θ expecting _exp, this angle records by knee joint angle sensor 72, and sends actuator position computing module 74 to and calculate the desired locations Y of piston rod 46 in executor 4 _exp; Knee joint angle sensor 72 is measured knee joint 3 anglec of rotation θ of current reality simultaneously _sensor, by actuator position computing module 74, calculate the physical location Y of current piston rod 46 _act; The desired locations Y of piston rod 46 _expwith physical location Y _actall be input to adder, through subtracting each other the deviate that the obtains input signal as controller module 75, controller module 75 is exported corresponding voltage control signal U _ctrl, voltage control signal U _ctrlby amplifier module 76, be converted to servo current signal I, servo current signal I inputs to hydraulic regulation module 77, calculates the aperture size x of servo valve 43 valves _vthereby, regulate the oily uninterrupted flowing in hydraulic cavities 48.In addition, the magnitude of voltage that gait judge module 73 is exported according to plantar pressure sensor 71 judges current gait.Support heavy burden compensating module 79 and provide according to current gait the support heavy burden balancing force F that current executor's 4 piston rods 46 need output _comp, support heavy burden balancing force F _compaperture size x with hydraulic valve valve _vinput to together executor's equivalent modules 78, by it, calculate the position Y that piston rod 46 should be exported _need.Like this by the above-mentioned closed loop feedback control to piston rod 46 positions, in the time of can making the anglec of rotation of shank part 1 relative thigh part 2 and the motion of people's lower limb, the angle of the desired variation of knee joint is consistent, and reaches the object of man-machine harmony campaign.At people's lower limb, in " single lower limb walking is supported " state, the magnitude of voltage that plantar pressure sensor 71 is exported is input in another adder, with the desired voltage values U being preset in control system 7 _expsubtract each other, the deviate obtaining is also input in controller module 75, as the input signal of force feedback control.Wherein, desired voltage values U _expthat support force F is expected in preassigned vola _expcorresponding magnitude of voltage, support force F is expected in vola _expafter can being set to deduct body weight, bear a heavy burden and overload carrying system device deadweight weight sum, U _expwith F _expcorresponding relation by the transformational relation between plantar pressure sensor 71 input and output, determined, different plantar pressure sensor, its transformational relation is also different.By the control of above-mentioned power closed loop feedback, can make piston rod 46 exert oneself fast at single lower limb walking driving phase like this, the perturbed force that compensation heavy burden produces, makes people have labour-saving sensation.

Executor 4 operation principle is as follows:

When control system 7 of the present invention is sent command signal, executor 4 electro-hydraulic reversing valve 44 forwards are connected, hydraulic oil enters in hydraulic cavities 48 by ozzle 42, under the effect of hydraulic oil, piston rod 46 moves so that the shank part 1 of firm limbs moves, and the interior airtight air in gas energy storage chamber 49 is compressed simultaneously; When control system 7, send signal, while making 44 times metas of electro-hydraulic reversing valve, hydraulic oil can not enter hydraulic cavities 48, and the fluid in hydraulic cavities 48 can not return to fuel tank, and executor 4 becomes rigid structural member, supports the load of bearing a heavy burden; When control system 7 is sent signal, electro-hydraulic reversing valve 44 is oppositely connected, hydraulic cavities 48 is connected with fuel tank, quick return under the combined effect of shank self moment of torsion when the compressed air of piston rod 46 in gas energy storage chamber 49 and human body natural walk, and the fluid in hydraulic cavities 48 is pushed back fuel tank.

Control method of the present invention, comprises the following steps:

1) plantar pressure sensor gathers plantar pressure information, knee joint angle sensor acquisition knee joint rotation angle information;

2) gait judge module by the plantar pressure sensor signal obtaining and in it preset given threshold value compare and judge, and according to judged result, select one of following three kinds of control instructions to carry out:

1. when when single lower limb walking is supported, executing location closed loop control and power closed loop control instruction, enter step 3);

2. when in both legs stationary support, executing location closed loop control instruction, enters step 4);

3. when when single lower limb walking swings, carry out gradual change open loop control instruction, enter step 5);

3) actuator position computing module is according to the knee joint angle expectancy changes value θ of the knee joint angle sensor output obtaining _exprelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod desired locations Y _exp, and export to adder;

Actuator position computing module is according to the knee joint angle actual change value θ of the knee joint angle sensor output obtaining _sensorrelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod physical location Y _act, and export to adder;

Adder is by the desired locations Y of the piston rod obtaining _expwith physical location Y _actsubtract each other, and the deviate calculating is exported to controller module;

Another adder is subtracted each other the plantar pressure sensor signal obtaining and the vola expected signal value being preset in control system, and the deviate calculating is exported to controller module;

Controller module is according to the desired locations Y of the piston rod obtaining _expwith physical location Y _actdeviate, and the deviation of plantar pressure sensor signal and vola expected signal value, and the mathematical model expression formula G of preset PID controller in it _pID, calculate voltage control signal U _ctrl, and output it to amplifier module, enter step 6);

4) by piston rod desired locations Y _expmaximum Y for people's executor's piston rod outgoing position when the both legs stationary support state is set _max, and export to adder;

Actuator position computing module is according to the knee joint angle actual change value θ of the knee joint angle sensor output obtaining _sensorrelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod physical location Y _act, and export to adder;

Adder is by the desired locations Y of the piston rod obtaining _expwith physical location Y _actsubtract each other, and the deviate calculating is exported to controller module;

Controller module is according to the desired locations Y of the piston rod obtaining _expwith physical location Y _actdeviate and the mathematical model expression formula G of the preset PID controller of Qi Nei _pID, calculate voltage control signal U _ctrl, and output it to amplifier module, enter step 6);

5) actuator position computing module is according to the knee joint angle expectancy changes value θ of the knee joint angle sensor output obtaining _exprelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod desired locations Y _exp, and export to adder;

Adder is by the desired locations Y of the piston rod obtaining _expdirectly export to controller module;

Controller module is according to the desired locations Y of the piston rod obtaining _exp, and the mathematical model expression formula G of its interior preset PID controller _pID, calculate voltage control signal U _ctrl, and output it to amplifier module;

6) amplifier module is by preset relational expression K in it _aby the voltage control signal U obtaining _ctrlbe converted to servo current amount I, and output it to hydraulic regulation module;

7) hydraulic regulation module is by preset relational expression G in it _svthe servo current amount I obtaining is converted to the aperture size x of servo valve valve _v, and output it to executor's equivalent modules;

8) executor's equivalent modules is by preset equivalent mathematical model expression formula G in it _eq, by the aperture size x of the servo valve valve obtaining _vwith the support heavy burden balancing force F that supports heavy burden compensating module and feed back _compbe converted to the position Y that piston rod should be exported _need, and output it to support heavy burden compensating module;

9) support heavy burden compensating module by its inner preset equivalent mathematical model G _compthe position Y that piston rod should be exported _needbe converted to the support heavy burden balancing force F that piston rod should be exported _comp, and it is fed back to executor's equivalent modules again, and return to step 1), until control system is sent order fulfillment circulation.

In above-described embodiment, knee joint angle sensor can adopt increment of rotation formula encoder.

In above-described embodiment, when the more accurate position servo of needs is followed the tracks of control, executor can also adopt motor power to drive the power drive of replacement hydraulic pump, there is similarity in its embodiment and hydraulic pump power drive mode, difference is: by conversion equipment, permanent magnetic brushless is rotatablely moved and is converted to Knee Joint Fluid cylinder pressure executor's round rectilinear motion, when controller only need to be controlled at different motion state, the rotating speed of motor size just can realize the accurate servo tracking control of different desired locations, thereby can realize the coordination control of some special action, as stair activity, kicking, squat down etc.

The various embodiments described above are only for illustrating the present invention, and wherein the structure of each part, connected mode etc. all can change to some extent, and every equivalents of carrying out on the basis of technical solution of the present invention and improvement, all should not get rid of outside protection scope of the present invention.

Claims (8)

1. the device of a human-machine coupling overload carrying system, comprise the firm limbs of coupling corresponding to human body lower extremity, described firm limbs comprise two groups of shank parts and thigh part, be connected to two knee joints and executor between described shank part and described thigh part, be connected to two sensing boots of described shank part bottom, be arranged on thigh part top described in two and be positioned at the backrest of human body back, and control system and power supply; Described control system comprises and is arranged on two groups of plantar pressure sensor in sensing boots described in two, it is characterized in that:

Described in each, executor comprises a hydraulic cylinder, and described hydraulic cylinder is connected to the middle part of described thigh part, and connects successively servo valve, electro-hydraulic reversing valve, fuel tank and oil pump by oil pipe, and described fuel tank and oil pump are arranged on described backrest bottom; The piston rod of described hydraulic cylinder connects the middle part of described shank part, and the inner of described piston rod is provided with a circle described hydraulic cylinder is separated into the flange in a hydraulic cavities and a gas energy storage chamber;

Described control system also comprises the two knee joint angle sensors that are arranged on knee joint place described in two, is arranged on the gait judge module in Control card in described backrest, actuator position computing module, controller module, amplifier module, hydraulic regulation module, executor's equivalent modules, supports heavy burden compensating module and two adders;

Described gait judge module by the plantar pressure sensor signal obtaining and in it preset given threshold value compare and judge; The piston rod position Y that the knee joint angle changing value θ that described actuator position computing module is exported the knee joint sensor obtaining and Qi Nei are preset and the relational expression of knee joint angle changing value θ, calculate piston rod position Y; Described controller module is by the mathematical model expression formula G of PID controller preset in it _pID, the deviate being obtained is converted to voltage control signal U _ctrl, and output it to described amplifier module; Described amplifier module is by preset relational expression K in it _aby the voltage control signal U of input _ctrlbe converted to servo current amount I, and output it to described hydraulic regulation module; Described hydraulic regulation module is by preset relational expression G in it _svthe servo current amount I of input is converted to the aperture size x of servo valve valve _v, and outputing it to described executor's equivalent modules, described executor's equivalent modules is by preset equivalent mathematical model expression formula G in it _eq, by the aperture size x of servo valve valve _vthe support heavy burden balancing force F feeding back with described support heavy burden compensating module _comp, be converted to the position Y that described piston rod should be exported _need, described support heavy burden compensating module is by its inner preset equivalent mathematical model G _compthe position Y that piston rod should be exported _needbe converted to the support heavy burden balancing force F that described piston rod should be exported _comp, and it is fed back to described executor's equivalent modules again.

2. the device of a kind of human-machine coupling overload carrying system as claimed in claim 1, it is characterized in that: described in one group, plantar pressure sensor is two, be placed on respectively the position contacting with rear heel with human body forefoot, described plantar pressure sensor output voltage signal.

3. the device of a kind of human-machine coupling overload carrying system as claimed in claim 1, is characterized in that: the mathematical model expression formula G of preset PID controller in described controller module _pIDfor:

G _PID＝K _P+T _Ds+T _I/s

In formula: K _pfor proportionality coefficient, T _dfor differential coefficient, T _ifor integral coefficient.

4. the device of a kind of human-machine coupling overload carrying system as claimed in claim 2, is characterized in that: the mathematical model expression formula G of preset PID controller in described controller module _pIDfor:

G _PID＝K _P+T _Ds+T _I/s

In formula: K _pfor proportionality coefficient, T _dfor differential coefficient, T _ifor integral coefficient.

5. the device of a kind of human-machine coupling overload carrying system as claimed in claim 1 or 2 or 3 or 4, is characterized in that: in described actuator position computing module, preset piston rod position Y and the relational expression of knee joint angle changing value θ are:

$Y=\sqrt{{\mathrm{Dist}1}^2+{\mathrm{Dist}2}^2-2\&times;\mathrm{Dist}1\&times;\mathrm{Dist}2\&times;\cos ({\mathrm{\&theta;}}_{\mathrm{init}}-\mathrm{\&theta;})}$

In formula: θ _initbe human body static when upright described in kneed initial angle value, Dist1 is that the junction point of described hydraulic cylinder on described thigh part is to the distance between described knee joint; Dist2 is that the junction point of described hydraulic cylinder on described shank part is to the distance between described knee joint;

Preset relational expression K in described amplifier module _afor:

$K_a=\frac{I}{U_{\mathrm{ctrl}}}$

In formula: K _ait is a gain amplifier constant;

Preset relational expression G in described hydraulic regulation module _svfor:

$G_{\mathrm{sv}}=\frac{x_v}{I}=\frac{K_{\mathrm{sv}}}{\frac{s^2}{{{\mathrm{\&omega;}}_{\mathrm{sv}}}^2}+\frac{2{\mathrm{\&xi;}}_{\mathrm{sv}}}{{\mathrm{\&omega;}}_{\mathrm{sv}}}s+1}$

In formula: ω _svthe natural frequency of described servo valve, ξ _svthe damping ratio of described servo valve, K _svit is the gain constant of described servo valve;

Preset equivalent mathematical model G in described executor's equivalent modules _eqfor:

$G_{\mathrm{eq}}=\frac{\frac{K_q}{A_p}}{\frac{V_t{m}_t}{4{\mathrm{\&beta;}}_e{A}_P^2}{s}^3+(\frac{m_t{K}_{\mathrm{ce}}}{A_p^2}+\frac{B_e{V}_t}{4{\mathrm{\&beta;}}_e{A}_p^2})s^2+(1+\frac{B_e{K}_{\mathrm{ce}}}{A_p^2}+\frac{{\mathrm{KK}}_{\mathrm{ce}}}{A_p^2})s+\frac{{\mathrm{KK}}_{\mathrm{ce}}}{A_p^2}}$

In formula: m _tthe quality of the shank part of described firm limbs, B _ethe damping of described firm limbs, β _ethe hydraulic oil elastic modelling quantity in described hydraulic cylinder, K _cebe the total flow-pressure coefficient of described servo valve, K is the spring rate of described firm limbs, K _qthe flow gain of described servo valve, A _pthe effective area of described piston rod, V _tit is the total measurement (volume) of described hydraulic cylinder;

Preset equivalent mathematical model G in described support heavy burden compensating module _compfor:

G _comp＝G _YtoFG _FtoFK

Wherein,

$G_{\mathrm{FtoFK}}=\frac{1}{K_q{A}_p}(K_{\mathrm{ce}}+\frac{V_t}{4{\mathrm{\&beta;}}_4}s)$

$G_{\mathrm{YtoF}}=\frac{F_{\mathrm{comp}}}{Y_{\mathrm{need}}}.$

6. the device of a kind of human-machine coupling overload carrying system as claimed in claim 5, is characterized in that: the gait obtaining according to described gait judge module, in following scope, choose G _ytoFvalue:

0≤G _YtoF≤1866

Wherein, when when single lower limb walking swings, G _ytoF=0.

7. the control method of a kind of human-machine coupling overload carrying system as described in claim 1～6 any one, comprises the following steps:

1) on the thigh part of the firm limbs of human-machine coupling overload carrying system, a hydraulic cylinder is set, the piston rod of hydraulic cylinder is connected on the shank part of firm limbs, a circle flange is set in the inner of piston rod hydraulic cylinder is separated into a hydraulic cavities and a gas energy storage chamber; Simultaneously, plantar pressure sensor and the knee joint angle sensor corresponding with human body are set in the control system of firm limbs, and are arranged on gait judge module, actuator position computing module, controller module, amplifier module, hydraulic regulation module, executor's equivalent modules, support heavy burden compensating module and two adders on a Control card;

2) plantar pressure sensor gathers plantar pressure information, knee joint angle sensor acquisition knee joint rotation angle information;

3) gait judge module by the plantar pressure sensor signal obtaining and in it preset given threshold value compare and judge, and according to judged result, select one of following three kinds of control instructions to carry out:

1. when when single lower limb walking is supported, executing location closed loop control and power closed loop control instruction, enter step 4);

2. when in both legs stationary support, executing location closed loop control instruction, enters step 5);

3. when when single lower limb walking swings, carry out gradual change open loop control instruction, enter step 6);

4) actuator position computing module is according to the knee joint angle expectancy changes value θ of the knee joint angle sensor output obtaining _exprelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod desired locations Y _exp, and export to adder;

Actuator position computing module is according to the knee joint angle actual change value θ of the knee joint angle sensor output obtaining _sensorrelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod physical location Y _act, and export to adder;

Adder is by the desired locations Y of the piston rod obtaining _expwith physical location Y _actsubtract each other, and the deviate calculating is exported to controller module;

Another adder is subtracted each other the plantar pressure sensor signal obtaining and the vola expected signal value being preset in control system, and the deviate calculating is exported to controller module;

Controller module is according to the desired locations Y of the piston rod obtaining _expwith physical location Y _actdeviate, and the deviation of plantar pressure sensor signal and vola expected signal value, and the mathematical model expression formula G of preset PID controller in it _pID, calculate voltage control signal U _ctrl, and output it to amplifier module, enter step 7);

5) by piston rod desired locations Y _expmaximum Y for people's executor's piston rod outgoing position when the both legs stationary support state is set _max, and export to adder;

Actuator position computing module is according to the knee joint angle actual change value θ of the knee joint angle sensor output obtaining _sensorrelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod physical location Y _act, and export to adder;

Adder is by the desired locations Y of the piston rod obtaining _expwith physical location Y _actsubtract each other, and the deviate calculating is exported to controller module;

Controller module is according to the desired locations Y of the piston rod obtaining _expwith physical location Y _actdeviate and the mathematical model expression formula G of the preset PID controller of Qi Nei _pID, calculate voltage control signal U _ctrl, and output it to amplifier module, enter step 7);

6) actuator position computing module is according to the knee joint angle expectancy changes value θ of the knee joint angle sensor output obtaining _exprelational expression with piston rod position Y and knee joint angle changing value θ preset in it, calculates piston rod desired locations Y _exp, and export to adder;

Adder is by the desired locations Y of the piston rod obtaining _expdirectly export to controller module;

Controller module is according to the desired locations Y of the piston rod obtaining _exp, and the mathematical model expression formula G of its interior preset PID controller _pID, calculate voltage control signal U _ctrl, and output it to amplifier module;

7) amplifier module is by preset relational expression K in it _aby the voltage control signal U obtaining _ctrlbe converted to servo current amount I, and output it to hydraulic regulation module;

8) hydraulic regulation module is by preset relational expression G in it _svthe servo current amount I obtaining is converted to the aperture size x of servo valve valve _v, and output it to executor's equivalent modules;

9) executor's equivalent modules is by preset equivalent mathematical model expression formula G in it _eq, by the aperture size x of the servo valve valve obtaining _vwith the support heavy burden balancing force F that supports heavy burden compensating module and feed back _compbe converted to the position Y that piston rod should be exported _need, and output it to support heavy burden compensating module;

10) support heavy burden compensating module by its inner preset equivalent mathematical model G _compthe position Y that piston rod should be exported _needbe converted to the support heavy burden balancing force F that piston rod should be exported _comp, and it is fed back to executor's equivalent modules again, and return to step 2), until control system is sent order fulfillment circulation.

8. the control method of a kind of human-machine coupling overload carrying system as claimed in claim 7, is characterized in that: in described step 4), support force F is expected in the vola desired signal and the preassigned vola that are preset in control system _expcorrespondence, support force F is expected in described vola _expfor bearing a heavy burden after deduction body weight and overload carrying system device deadweight weight sum.

Images