CN105045259B - A kind of assistant robot man-machine interface based on multisensor and avoidance obstacle method thereof - Google Patents

Abstract

The invention discloses a kind of assistant robot man-machine interface based on multisensor and avoidance obstacle method thereof; Man-machine interface comprises pressure acquisition module, obstacle detection module and controller; Pressure acquisition module is for detecting the acting force of operator's hand; Obstacle detection module is for detecting periphery barrier; Controller is used for the speed calculating assistant robot according to the data of pressure acquisition module acquires and the data of obstacle detection module detection, and realizes walk help and barrier avoiding function according to the speeds control assistant robot of assistant robot.Obstacle detection module is made up of laser sensor and high speed USB data line, can detect periphery barrier; Controller communicates with obstacle detection module with pressure acquisition module, calculates suitable speed and is sent to external communication interface, and can guide the operation of operator the data analysis gathered, and ensures to control safety.Precise control of the present invention, real-time is high, portable strong and cheap.

Description

A kind of assistant robot man-machine interface based on multisensor and avoidance obstacle method thereof

Technical field

The invention belongs to man-machine interaction, rehabilitation accessory field, more specifically, relate to a kind of assistant robot man-machine interface based on multisensor and avoidance obstacle method thereof.

Background technology

, as a populous nation, about there are 1.5 hundred million the elderlys in China, and disabled person 8,296 ten thousand, relate to 2.6 hundred million family populations.Social total number of persons more than 10% is accounted for according to the crowd of more than 60 years old that the World Health Organization (WHO) proposes, or the crowd of over-65s is astogeny country when accounting for more than 7% of social total number of persons, according to statistics in 2000, the coefficient of aged population 10.18% of China more than 60 years old, China oneself enter astogeny society, will up to more than 15% to the year two thousand twenty China the elderly, the life health problem of the elderly, will become social concern.Along with China enters aging society, the elderly and the various disease of old people patient of walking function obstacle increase year by year, seriously have impact on their quality of life, bring white elephant to family and society.

Inconvenient walking is almost the most serious problems of puzzlement the elderly and lower limb disabled normal life, for supporting and improve the walking ability of various lower limb disorder crowd, walk help lower limb rehabilitation robot has become the study hotspot in domestic and international robot and medical science of recovery therapy field.Lower limb rehabilitation robot has the device such as assistant robot and Intelligent crutch, and ultimate principle is the force signal utilizing sensing device to extract patient's upper limbs, judges the intention of patient according to treated force signal, thus helps patient to complete the movement of respective direction.With regard to current sensing device, a kind of scheme is the six-dimension force sensor utilizing price high, improves the cost of assistant robot undoubtedly; Another kind is by multiple one dimension force sensor composition sensor array, is undertaken calculating by the formula of corresponding data and design thus is judged the motion intention of people.This scheme can reduce the cost of man-machine interface greatly, but its research is still in the junior stage, and existing design exists various defect in various degree, effectively can not gather the data of the power of related direction.

Meanwhile, the user of assistant robot system mostly is the elderly, and their general eyesight is poor, and more likely operates assistant robot mistakenly than ordinary person thus bring potential safety hazard.But current assistant robot system lacks security mechanism mostly.

Therefore need badly at present to develop and a set ofly can effectively detect patient's acting force, cheap, simultaneously can the issuable mistake intention of corrective operations person man-machine interface with realize walk help lower limb rehabilitation robot and patient moving be intended between Collaborative Control, the adaptive capacity to environment simultaneously strengthened, to obtain better walk help effect, to expect progressively to realize assistant robot commercialization and industrialization.

Summary of the invention

For the defect of prior art, the object of the present invention is to provide and a kind ofly control assistant robot man-machine interface effective, convenient and reliable and with low cost and avoidance obstacle method thereof.

The invention provides a kind of assistant robot man-machine interface based on multisensor, comprise pressure acquisition module, obstacle detection module and controller; Described pressure acquisition module is for detecting the acting force of operator's hand; Described obstacle detection module is for detecting periphery barrier; Described controller and described pressure acquisition module and described obstacle detection model calling, for calculating the speed of assistant robot according to the data of described pressure acquisition module acquires and the data of described obstacle detection module detection, and assistant robot realizes walk help and barrier avoiding function according to the speeds control of described assistant robot.

Further, described pressure acquisition module comprises Force sensor, Signal-regulated kinase and data acquisition module; Described Force sensor is two layers of tube-in-tube structure, and skin is the inner right cylinder being become rectangular parallelepiped by hollow out, internal layer is square cylinder, has gap between right cylinder and square cylinder, is respectively arranged with 1 FSR sensor fills described gap in four sides of internal layer square cylinder; For the component of acquisition operations person right-hand man acting force vertical and horizontal; Described Signal-regulated kinase is used for nursing one's health rear output to the acting force that described Force sensor gathers; Described data acquisition module obtains magnitude of voltage after being used for carrying out AD conversion to the data after conditioning.

Further, described obstacle detection module comprises laser sensor and the USB high speed data lines for connecting described laser sensor and described controller; The obstacle information of collection for gathering the obstacle information of surrounding enviroment, and is sent to controller by described USB data line by described laser sensor.

Further, described controller is used for, according to Artificial Potential Field Method, the obstacle information of obstacle detection module acquires is converted to repulsion; Calculate repulsion and operator's acting force with joint efforts, and be converted to the speed realizing walk help for controlling assistant robot by making a concerted effort.

Present invention also offers a kind of avoidance obstacle method of the assistant robot man-machine interface based on multisensor, comprise the steps:

(1) the acting force information of acquisition operations person's hand, and detect the range information between barrier and assistant robot;

(2) according to described acting force information acquisition operator acting force in all directions; The repulsion raw according to described range information acquired disturbance produce;

(3) obtain the intention power of operator according to described repulsion and operator's acting force in all directions, and according to open loop admittance control algorithms, the intention power of operator is converted to speed, thus control assistant robot keeps away barrier safely.

Further, the repulsion that the barrier calculated according to Artificial Potential Field Method produces is F _ri=K × (r-R ₀) ^-n, K, R in formula Chinese style ₀, n is constant, wherein n generally gets positive integer; R is the distance of barrier and assistant robot, F _rifor the size of repulsion.

Further, following principle is followed in the motion of described assistant robot:

(1) if X-direction is not 0 with joint efforts and right-hand man's force direction is consistent, so resultant direction motion of Robot X-axis;

(2) if Y direction is not 0 with joint efforts, so resultant direction motion of Robot Y-axis;

(3) if right-hand man's force direction of X-axis is contrary, so according to arm of force factored moment, Robot moment direction rotates;

Wherein, true origin is assistant robot central point, and X-direction is the relative dead ahead of assistant robot; Y direction refers to the relative left of assistant robot.

Present invention also offers a kind of avoidance obstacle method of the assistant robot man-machine interface based on multisensor, comprise the steps:

When there is barrier in urgent Bi Zhang district, judge the intention power F of operator _iwhether have the component of X-axis negative direction, if so, then assistant robot keeps out of the way barrier after deferring to the intention of operator, and if not, then assistant robot will take the mode of lateral translation to evade the barrier in urgent Bi Zhang district.

Further, described urgent Bi Zhang district is rectangle, and the length of rectangle is Length, and width is Width, when the distance L between laser sensor and a sensing point of laser sensor meets following formula, $\left\{\begin{array}{c}|L\&times;\cos \mathrm{\&alpha;}|<\mathrm{Length}\\ |L\&times;\sin \mathrm{\&alpha;}|<\mathrm{Width}\end{array}\right.;$ Then think that barrier is in urgent Bi Zhang district, wherein α is certain point of barrier and the angle of described X-axis.

Further, when barrier is in urgent Bi Zhang district, meet the number of the point of rectangle condition by the left of statistics X-axis and right side, translation is carried out in few side of selecting to count.Whether have enough keep away hinder space, can change translation direction or stopping according to detection case if detecting in real time in translation motion on translation direction.

The invention has the advantages that, first utilize the Force sensor of cheap FSR sensor and design to instead of traditional six-axis force sensor in operator's acting force context of detection, while reducing costs, effectively can detect again the acting force of operator; Utilize laser sensor to scan periphery barrier, the obstacle information using scanning to obtain guides operator and corrects, and ensure that the safety of operator and assistant robot; The control method utilizing multithreading to realize meets the demand that assistant robot keeps away barrier and walk help simultaneously, and ensure that real-time; Relatively simple structure makes this assistant robot man-machine interface go for the assistant robot of various physical construction, is easy to apply, meets the demand that user is different.

Accompanying drawing explanation

Fig. 1 is multisensor assistant robot man-machine interface system block diagram provided by the invention.

Fig. 2 is an application example schematic diagram of the embodiment of the present invention.

Fig. 3 is the mechanical hook-up schematic diagram of FSR used in the present invention (ForceSensingRegisters, power sensing record cell) sensor.

Fig. 4 is the schematic diagram of the signal conditioning circuit of FSR sensor used in the present invention, and wherein (a) is the physical circuit figure of amplifying circuit, and (b) is the physical circuit figure of generating circuit from reference voltage.

Fig. 5 is the force analysis figure that the embodiment of the present invention is applied to an assistant robot example.

Fig. 6 is the fundamental diagram of the laser sensor that the embodiment of the present invention uses.

Fig. 7 is the structural representation of barrier described in the invention.

Fig. 8 is the schematic diagram of the barrier merge algorithm that the present invention applies; Wherein (a) is the method for expressing before two adjacent barrier merge, and (b) is the method for expressing after two adjacent barrier merge.

Fig. 9 is the urgent obstacle-avoidance area schematic diagram of barrier scheme of promptly the keeping away setting that the present invention proposes.

Figure 10 is the state transition graph promptly keeping away barrier scheme that the present invention proposes.

Figure 11 is the multithread programs process flow diagram of the embodiment of the present invention.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

The invention provides and a kind ofly control assistant robot man-machine interface effective, convenient and reliable and with low cost and avoidance obstacle method thereof.

As shown in Figure 1, man-machine interface comprises pressure acquisition module 1, obstacle detection module 2 and controller 3; Pressure acquisition module 1 is for detecting the acting force of operator's hand; Obstacle detection module 2 is for detecting periphery barrier; Controller 3 is connected with pressure acquisition module 1 and obstacle detection module 2, the data detected for the data that gather according to pressure acquisition module 1 and obstacle detection module 2 calculate the speed of assistant robot, and assistant robot realizes walk help and barrier avoiding function according to the speeds control of assistant robot.

Pressure acquisition module 1 comprises the Force sensor 11, Signal-regulated kinase 12 and the data acquisition module 13 that connect successively; Force sensor 11 is two layers of tube-in-tube structure, and outer is the inner right cylinder being become rectangular parallelepiped by hollow out, and internal layer is square cylinder; There is gap between right cylinder and square cylinder, be respectively arranged with 1 FSR sensor in four sides of the square cylinder of every one deck and fill described gap; Force sensor 11 is for the component of acquisition operations person right-hand man acting force vertical and horizontal; Signal-regulated kinase 12 nurses one's health rear output for the acting force gathered described Force sensor; Data acquisition module 13 obtains magnitude of voltage after carrying out AD conversion to the data after conditioning.

Obstacle detection module 2 comprises laser sensor 21 and the high speed USB data line for connecting described laser sensor 21 and controller 3; The obstacle information of collection for gathering the obstacle information of surrounding enviroment, and is sent to controller by described high speed USB data line by laser sensor 21.

Controller 3 is for being converted to repulsion according to Artificial Potential Field Method by the obstacle information that obstacle detection module 2 gathers; Calculate repulsion and operator's acting force with joint efforts, and be converted to the speed realizing walk help for controlling assistant robot by making a concerted effort.

Fig. 2 shows an application example of the assistant robot man-machine interface that the embodiment of the present invention provides; For pressure acquisition module 1, Force sensor 11 comprises 8 FSR ((ForceSensingRegisters, power sensing record cell)) sensor, its physical construction as shown in Figure 3, is through the Force sensor of specified arrangement and machining; Binding signal conditioning module 12 and data acquisition module 13, pressure acquisition module 1 can detect the acting force of operator's hand.Obstacle detection module 2 is made up of with the high speed USB data line for being connected with controller 3 laser sensor 21, can detect periphery barrier; Industrial computer selected by controller 3, it communicates with obstacle detection 2 module with pressure acquisition module 1, carries out comprehensive analysis and calculation to the data that their gather, and obtains a suitable speed and is sent to external communication interface, and can guide the operation of operator, ensure to control safety.The external communication interface be connected with controller is in the present embodiment for being connected omnidirectional's motor chassis, and motor chassis can drive the motion of assistant robot.

Fig. 3 is the mechanical schematic diagram of the Force sensor 11 in pressure acquisition module 1 of the present invention, has showed operator in Fig. 2 and has held part, be i.e. the detailed design of Force sensor 11.Force sensor 11 is the two layers of tube-in-tube structure in two, left and right, and outer is the inner right cylinder being become rectangular parallelepiped by hollow out, and internal layer is square cylinder; 4 FSR sensors through unified process have been secured on four sides all around of an internal layer rectangle cylinder respectively.Have certain gap between internal layer and skin, the sensor that this gap can be attached to the process of square cylinder side by 4 is filled just.In embodiments of the present invention, the tow sides of FSR sensor have pasted the rubber of flexible smooth, the outside of rubber is part of the force, and external pressure can fully be reacted in the change of resistance by the FSR sensor of so process, thus the obvious voltage signal that changes.When hand applies the thrust of any direction to the right cylinder of outside, Force decomposition can be the component of longitudinally (front and back) and horizontal (left and right) by this Force sensor 11.Force sensor 11 is made of metal, and therefore it can not produce deformation because of grip, has well filtered grip useless in force signal, and obtains thrust or the pulling force of needs.

Fig. 4 is the schematic diagram of the Signal-regulated kinase in the present invention.Signal-regulated kinase comprises simple and easy amplifying circuit and reference voltage generating circuit.Reference voltage generating circuit is made up of bleeder circuit and voltage follower circuit, and its output terminal is linked into the positive input V as the reference voltage of simple and easy amplifying circuit _ref.Simple and easy amplifying circuit is the in-phase amplification circuit be made up of operational amplifier, and FSR sensor is linked in in-phase amplification circuit as resistance, if its resistance is R _fsr.The size of the known pressure of product information and resistance of consulting FSR sensor is approximated to inverse proportion funtcional relationship, and along with the increase of pressure, the resistance of FSR sensor will reduce rapidly.If F=N × R _fsr ^-1(1); In-phase amplifier output voltage V _ocan be expressed as: V _o=V _ref× (1+R ₁× R _fsr ^-1) ... (2); Formula (1) is substituted into formula (2) can obtain: V _o=V _ref× (1+R ₁× F × N ^-1) ... (3); Wherein F is the pressure size acted on FSR sensor; N is scale-up factor; R ₁for the variable-resistance resistance of amplifying circuit simple and easy in Fig. 4.

From formula (1) (2), when pressure is very little, the resistance R of the FSR sensor in in-phase amplification circuit _fsrmuch larger than variable resistor R ₁value, the output of voltage follower is reference voltage V _ref.As can be seen from formula (3), the circuit design that the present invention adopts can allow the relation of pressure and output voltage become linear relationship within the specific limits, and output voltage linearly increases along with the increase of pressure.The input interface of circuit is divided into two groups, often organizes all accessible 4 FSR sensors (totally 8), just accessible necessary 8 the FSR sensors of Force sensor 11.Output interface has 10 pins, comprises output voltage and two ground wires of No. 8 voltage followers.Output interface is connected with data acquisition module 13 (for grind China USB4716), therefore output pin put in order consistent with the arrangement of the analog voltage input pin of data acquisition module 13 so that wiring.

Data acquisition module 13 used in the present invention can Shi Yanhua company produce data collecting card USB4716, the data collecting card that any one can carry out the AD conversion being greater than 12 can be changed as required into.Due to the product that data collecting card USB4716 is technically very ripe, therefore on hardware without the need to any change, need to do writing control program according to product description completes corresponding AD conversion work by it exactly.

Shown in Fig. 5 is the force analysis figure of embodiment of the present invention pressure acquisition module 11, as recited in claim 7, being forward X-axis positive dirction, it is left Y-axis positive dirction, set up the local coordinate system of assistant robot, pressure acquisition module is consistent with the coordinate system on the chassis used in obstacle detection module and the embodiment of the present invention, calculates because unified coordinate system is conducive to simplifying.Composition graphs 2 easy to understand, in Fig. 5, FHL and FHR represents the acting force of operator's left hand and right hand respectively, wherein F _lX, F _lY, F _rX, F _rYfHL and FHR respectively along the decomposition of X-axis and Y direction.F _rthe repulsion that preceding object thing that the obstacle information detected according to obstacle detection module calculates produces assistant robot.According to the unified coordinate system that the present embodiment is set up, composition graphs 5, if the sleeve force value measured by FSR sensor be positioned in X-axis positive dirction in the left side is F ₁, the measured value of each FSR sensor is followed successively by F in the direction of the clock ₁~ F ₄, in like manner, the measured value of the right sleeve FSR sensor is F ₅~ F ₈.We can by the component F of the acting force of operator right-hand man along X-axis and Y-axis thus ₁~ F ₈numerical value plus-minus represent, shown in (4): $\left\{\begin{array}{c}{F}_{1X}=F_3-F_1\\ F_{1Y}=F_4-F_2\\ F_{\mathrm{rX}}=F_7-F_5\\ F_{\mathrm{rY}}=F_8-F_6\end{array}\right.---\left(4\right).$

The movement of assistant robot mainly can be divided into anterior-posterior translation, left and right translation and rotary motion.The data of Force sensor collection are that the power of two hands is respectively at the component of X-axis and Y-axis acting force.The repulsion that barrier produces carries out decomposing and calculates by controller 3 makes a concerted effort, and so can control the motion of assistant robot according to following basic skills:

(1) if X-direction is not 0 with joint efforts and right-hand man's force direction is consistent, so assistant robot moves along the resultant direction of X-axis;

(2) if Y direction makes a concerted effort not to be 0, so assistant robot moves along the resultant direction of Y-axis;

(3) if right-hand man's force direction of X-axis is contrary, so according to arm of force factored moment, assistant robot rotates along moment direction;

Above three basic skills can combination in any, thus makes assistant robot on two dimensional surface, complete all basic exercises.

Laser sensor 21 in the embodiment of the present invention is models that Japanese Bei Yang company produces is the laser sensor of URG-04LX-UG01, its fundamental diagram as shown in Figure 6, by the unified coordinate system set up before, definition X-axis positive dirction is 0 °, and so this laser sensor can realize the comprehensive scanning by counterclockwise carrying out from-120 ° to 120 °.The effect of laser sensor 21 is barriers of the periphery of scanning assistant robot, and according to the repulsion of Artificial Potential Field Method dyscalculia thing, specific as follows:

The fundamental formular that Artificial Potential Field Method repulsion calculates is as follows: F _ri=K × (r-R ₀) ^-n(5); K, R in formula ₀, n is constant, generally gets positive integer.R is the distance of barrier and robot, F _rifor the size of repulsion.

For each barrier in environment, { rEdge, rAngle, lEdge, lAngle, Force, Angle} are used as the location contents in barrier chained list to design six tuple structure.As shown in Figure 7, laser sensor 21 at O point, rEdge represent on the right of barrier along with the distance of laser sensor 21 | OB|, rAngle represent on the right of barrier along the angle ∠ BOX with laser sensor 21 line and X-axis positive dirction.In like manner, lEdge and lAngle represents the distance value of barrier left margin respectively | OA| and angle ∠ AOX.Force represents the size of repulsion, and Angle represents the direction of repulsion and the angle of X-axis positive axis.Herein for each barrier, choose ∠ AOB angular bisector OD direction that barrier edge and laser sensor 21 form as repulsion direction, r=|OD| substitutes into formula (5), can obtain the size of the repulsion Force that single barrier produces: F _ri=K × (| OD|-R ₀) ^-n(6); It should be noted that, when two obstacle distances are very near, the gap between them may be not enough to allow assistant robot therefrom safety.The repulsion produced due to barrier is only relevant with the relative distance of assistant robot with it, and the repulsion of the obstacle cluster generation in same place may be far longer than the acting force of operator after vector is cumulative, thus obstruction assistant robot is normally advanced.For avoiding the double counting of the repulsion in close direction, the barrier of close together should be carried out merging treatment.Fig. 8 gives the example that a barrier merges.

For two adjacent barriers as Fig. 8 (a), easily obtain the value α of ∠ BOC according to six tuple structure designed before, according to the cosine law, obtain the gap of barrier 1 and barrier 2 | BC|: $\left|\mathrm{BC}\right|=\sqrt{{\left|\mathrm{OB}\right|}^2+{\left|\mathrm{OC}\right|}^2-2\left|\mathrm{OB}\right|\left|\mathrm{OC}\right|\cos \mathrm{\&alpha;}}......\left(7\right);$

If | BC| is less than the size of the assistant robot of application the present embodiment, then merge barrier, as shown in Fig. 8 (b).Using the right of barrier 1 in Fig. 8 (a) along the left margin OA of OD and barrier 2 as the edge merging obstruction, OE is the angular bisector of △ AOD, OE length can be obtained according to leg-of-mutton angular bisector formula | OE|, brings the repulsion F that (5) can obtain merging obstruction generation into _ri=K × (| OE|-R ₀) ^-n(8);

Noting, calculate | OE| instead of the scan values of directly getting OE direction laser sensor 21 are that now laser sensor 21 can't detect barrier, may affect the calculating of repulsion because line segment OE extended line may just through the gap of two barriers.

Barrier is finally stored in obstacle information chained list after merging, final repulsion F _rfor the repulsion F that each barrier produces _obivector sum: i is i-th barrier in obstacle information chained list, and n is the sum of barrier;

In practice, for the ease of calculating and merging with operator's hand acting force, we calculate the component of repulsion in X-axis and Y direction respectively and sue for peace.The direction of the positive and negative and coordinate axis of power defines consistent. $F_{\mathrm{obX}}=\underset{i=0}{\overset{n}{\mathrm{\&Sigma;}}}{F}_{\mathrm{obiX}}=-\underset{i=0}{\overset{n}{\mathrm{\&Sigma;}}}\left|F_{\mathrm{obi}}\right|\cos {\mathrm{\&theta;}}_i......\left(10\right),F_{\mathrm{obY}}=\underset{i=0}{\overset{n}{\mathrm{\&Sigma;}}}{F}_{\mathrm{obiY}}=-\underset{i=0}{\overset{n}{\mathrm{\&Sigma;}}}\left|F_{\mathrm{obi}}\right|\sin {\mathrm{\&theta;}}_i......$ $\left(11\right);$ The repulsion vector finally obtained is F _r=[F _obXf _obY0] ^t.

Before in the description of Fig. 5, we have obtained the variable F representing operator's both hands force component _lX, F _lY, F _rX, F _rY.We can with four dimensional vector F _srepresent the input quantity of applied force vector as man-machine interface of operator, with a tri-vector F _irepresent the intention of operator, claim vectorial F _ifor the intention force vector of operator.Then have: F _s=[F _lXf _lYf _rXf _rY] ^t(12); F _i=[F _xf _ym _z] ^t(13);

For F _i, F _xrepresent the intention power of operator in X-direction, F _yrepresent the intention power of operator in Y direction, M _zrepresenting the rotary torque that operator applies assistant robot, is just with counter clockwise direction.In conjunction with before according to Artificial Potential Field Method calculate repulsion vector F _r, have following formula to set up: F _i=E _iSf _s+ F _r(14);

The repulsion vector calculated of the applied force vector of operator and Artificial Potential Field Method combines, as the intention force vector of operator by formula (14).Wherein E _iSthe transition matrix of 3 × 4: $E_{\mathrm{IS}}=\left[\begin{array}{cccc}1& 0& 1& 0\\ 0& 1& 0& 1\\ -L& 0& L& 0\end{array}\right]......\left(15\right),$ Wherein L represents the half of the width of assistant robot shown in Fig. 5.

Obtain operator and be intended to force vector F _iafter, use open loop admittance control algorithms that the intention force vector of operator is converted to velocity vector.If the intention force vector of operator is F _{i (s)}, the velocity vector that assistant robot exports is V _(s), then can obtain according to the transport function of admittance control algorithms: wherein K is scale-up factor, and τ is time constant.

Write as continued time domain model to have: $\mathrm{\&tau;}\&CenterDot;\frac{\mathrm{dV}\left(t\right)}{\mathrm{dt}}+V\left(t\right)=K\&CenterDot;F_I\left(t\right)......\left(17\right);$

Discretize: $\mathrm{\&tau;}\&CenterDot;\frac{V\left(n\right)-V(n-1)}{T}+V\left(n\right)=K\&CenterDot;F_I\left(n\right)......\left(18\right);$ Abbreviation: $V\left(n\right)=K\&CenterDot;\frac{T}{T+\mathrm{\&tau;}}\&CenterDot;F_I\left(n\right)+\frac{\mathrm{\&tau;}}{T+\mathrm{\&tau;}}\&CenterDot;V(n-1)......\left(19\right);$

Artificial Potential Field Method combines with admittance control algorithms and is applied to assistant robot distance barrier situation far away, operator and periphery barrier can be effectively guided to keep at a distance, simultaneously in order to ensure the security of assistant robot man-machine interface, the present embodiment devises one and promptly keeps away barrier scheme, and details are as follows:

When may collide at any time, must take promptly to keep away barrier measure to ensure the safety of operator and assistant robot when barrier and assistant robot hypotelorism.First the present embodiment divides urgent Bi Zhang district, when finding barrier in urgent Bi Zhang district, if the intention force vector F of operator _ihave the component of X-axis negative direction, assistant robot keeps out of the way barrier by after the intention deferring to operator, otherwise assistant robot will take the mode of lateral translation to attempt the barrier evading urgent Bi Zhang district.

The choosing method in urgent Bi Zhang district uses rectangle condition, and as shown in Figure 9, urgent obstacle-avoidance area is the rectangle in Fig. 9, and laser sensor 21 is at O point place.Then judge to there is barrier in rectangular area when laser sensor 21 exists when any one analyzing spot meets rectangle condition, rectangle condition is described below:

If the sensing point that A (x, y) is laser sensor, | OA|=L.If rectangle length is Length, width is Width, and when the part that cooks noodle is set up, rectangle condition is set up; $\left\{\begin{array}{c}|L\&times;\cos \mathrm{\&alpha;}|<\mathrm{Length}\\ |L\&times;\sin \mathrm{\&alpha;}|<\mathrm{Width}\end{array}\right....\left(20\right),$ α is certain point of barrier and the angle of X-axis.

Now start and promptly keep away barrier scheme.Promptly keep away barrier scheme first to select the positive dirction of Y-axis or negative direction to carry out translation to keep away barrier, set direction make use of a kind of Voting Algorithm, is namely boundary with X-axis, and on the left of statistics X-axis and right side meets the number of the point of rectangle condition, and translation is carried out in few side of selecting to count.In fact this Voting Algorithm have selected an original state of assistant robot.Keep away assistant robot in the process of barrier in translation and detect the distance of assistant robot to edge body of wall in real time as Fig. 9, once find that this distance is less than safe distance, then change motion state immediately.Assistant robot can be changed when urgent obstacle-avoidance area exists barrier between various state, concrete barrier scheme of promptly keeping away can represent with state transition graph as shown in Figure 10, below form describe the various conditions of various state and State Transferring in detail.

State	Explanation
		0	Clear in urgent Bi Zhang district, performs admittance control algorithms and Artificial Potential Field Method
1	There is barrier in urgent Bi Zhang district, and robot moves right
		2	There is barrier in urgent Bi Zhang district, and robot is moved to the left

3	Assistant robot emergent stopping

The embodiment of the present invention adopts multithreading to realize above scheme, the multithread programs process flow diagram be summarised as shown in Figure 11 that the method more than described can be concise and to the point.After controller initialization, main thread and a thread successively start, and they are independent, concurrent working, and all carry out periodic duty.Two threads use repulsion vector F _rthe control to assistant robot is jointly completed with state variable State.State variable State initial value is 0, represents that transport condition is normal.

The job step of propping up thread is as follows:

First (result is an array set to extract the scanning result of laser sensor, the obstacle distance of certain angle in each element representation sweep limit in set), according to scanning result, first judge whether there is barrier in urgent Bi Zhang district, if existed, so change the value of state variable State according to the urgent obstacle avoidance algorithm described in Figure 10.

If there is no, so according to six tuple structure { rEdge of the barrier model set up in Fig. 7 and barrier, rAngle, lEdge, lAngle, Force, Angle}, first can obtain rEdge=|OB| from laser sensor, rAngle=∠ BOX, lEdge=|OA|, lAngle=∠ AOX, can obtain Angle=∠ DOX=1/2 × (∠ AOX+ ∠ BOX) according to rAngle and lAngle, and then can according to Angle, distance value corresponding to Angle is read by laser sensor | OD|, recycling (6) formula calculates the size of repulsion Force.Can calculate the information of all periphery obstacles of single pass by above method, form barrier chained list, the location contents of chained list is above-mentioned six tuple structure.

After setting up barrier chained list, whether the gap (BC in Fig. 8 (a)) utilizing the cosine law (formula (7)) to calculate between adjacent barrier can make assistant robot pass through, if can not, two barriers are merged into one and carries out processing (Fig. 8 (b)), and recalculate repulsion according to formula (8).After barrier chained list is arranged, the repulsion that barriers all in chained list produce is carried out to vector summing and decomposes (formula (9) (10) (11)) along the coordinate axis set, obtains the vectorial F that makes a concerted effort of the repulsion that in barrier chained list, all barriers produce _r=[F _obXf _obY0] ^t, finally change the value of state variable State into 0.It is more than the action of a thread one-period.

Main thread job step is as follows:

After main thread starts AD conversion, AD conversion result is read in timing, the acting force numerical value F that the 8 road FSR sensors that namely data acquisition module 13 gathers detect ₁~ F ₈, utilize formula (4) to calculate; F _s=[F _lXf _lYf _rXf _rY] ^t, according to the repulsion vector calculation result F of a thread _r=[F _obXf _obY0] ^twith the intention force vector F of formula (14) calculating operation person _i=[F _xf _ym _z] ^t, then calculate final output speed V according to formula (19) _n=[V _xv _yv _z] ^t.The value of last reading state variable State, if be 0, by result of calculation V _nbe sent to base plate electric machine, assistant robot is with speed V _nmotion; If be 1, assistant robot keeps away barrier with fixed speed to right translation; If be 2, assistant robot keeps away barrier with fixed speed to left; If be 3, assistant robot emergent stopping.

In sum, this embodiment has that structure is simple, easy-to-use, versatility is high, real-time and security good, and the feature that cost is comparatively cheap.Can to be applied to easily in general assistant robot system thus to strengthen the locomotor activity of locomotor activity damage and amblyopia patient, improving their quality of life.

Those skilled in the art will readily understand; the foregoing is only preferred embodiment of the present invention; not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (7)

1. based on an assistant robot man-machine interface for multisensor, it is characterized in that, comprise pressure acquisition module (1), obstacle detection module (2) and controller (3);

Described pressure acquisition module (1) is for detecting the acting force of operator's hand;

Described obstacle detection module (2) is for detecting periphery barrier;

Described controller (3) is connected with described pressure acquisition module (1) and described obstacle detection module (2), the data detected for the data that gather according to described pressure acquisition module (1) and described obstacle detection module (2) calculate the speed of assistant robot, and assistant robot realizes walk help and barrier avoiding function according to the speeds control of described assistant robot.

2. assistant robot man-machine interface as claimed in claim 1, it is characterized in that, described pressure acquisition module (1) comprises Force sensor (11), Signal-regulated kinase (12) and data acquisition module (13);

Described Force sensor (11) is two layers of tube-in-tube structure, and skin is the inner right cylinder being become rectangular parallelepiped by hollow out, internal layer is square cylinder, has gap between right cylinder and square cylinder, is respectively arranged with 1 FSR sensor fills described gap in four sides of internal layer square cylinder; For the component of acquisition operations person right-hand man acting force vertical and horizontal;

Described Signal-regulated kinase (12) nurses one's health rear output for the acting force gathered described Force sensor (11);

Described data acquisition module (13) obtains magnitude of voltage after carrying out AD conversion to the data after conditioning.

3. assistant robot man-machine interface as claimed in claim 1, it is characterized in that, described obstacle detection module (2) comprises laser sensor (21) and the USB high speed data lines for connecting described laser sensor (21) and described controller (3); The obstacle information of collection for gathering the obstacle information of surrounding enviroment, and is sent to controller (3) by described USB data line by described laser sensor (21).

4. the assistant robot man-machine interface as described in any one of claim 1-3, is characterized in that, described controller is used for, according to Artificial Potential Field Method, the obstacle information that obstacle detection module (2) gathers is converted to repulsion; Calculate repulsion and operator's acting force with joint efforts, and be converted to the speed realizing walk help for controlling assistant robot by making a concerted effort.

5., based on an avoidance obstacle method for the assistant robot man-machine interface of multisensor, it is characterized in that, comprise the steps:

(1) the acting force information of acquisition operations person's hand, and detect the range information between barrier and assistant robot;

(2) according to described acting force information acquisition operator acting force in all directions; The repulsion raw according to described range information acquired disturbance produce;

(3) obtain the intention power of operator according to described repulsion and operator's acting force in all directions, and according to open loop admittance control algorithms, the intention power of operator is converted to speed, thus control assistant robot keeps away barrier safely.

6. avoidance obstacle method as claimed in claim 5, is characterized in that, is F according to the repulsion that the barrier of Artificial Potential Field Method calculating produces _ri=K × (r-R ₀) ^-n, K, R in formula ₀, n is constant, wherein n generally gets positive integer; R is the distance of barrier and assistant robot, F _rifor the size of repulsion.

7. avoidance obstacle method as claimed in claim 5, it is characterized in that, following principle is followed in the motion of described assistant robot:

(1) if X-direction is not 0 with joint efforts and right-hand man's force direction is consistent, so resultant direction motion of Robot X-axis;

(2) if Y direction is not 0 with joint efforts, so resultant direction motion of Robot Y-axis;

(3) if right-hand man's force direction of X-axis is contrary, so according to arm of force factored moment, Robot moment direction rotates;

Wherein, true origin is assistant robot central point, and X-direction is the relative dead ahead of assistant robot; Y direction refers to the relative left of assistant robot.