JPH10105235A - Continuous position detecting and controlling device for traveling object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously and accurately detect the mutual relative position between a guidance position mark and a traveling object and its traveling direction by performing an integrated operation of signals of a sensor heads which are assembled from plural position detecting sensors that are the same type of a function. SOLUTION: Four position detecting coils 16a to 16d are arranged on axes which are orthogonally crossed. When detection values of the coils 16a to 16d are made as VA to VD, the center Om of a circular mark plate 61 (position mark plate 11) is on a circular arc with the radius of displacement distance rA which corresponds to a detection value VA from the center A of the coil 16a, and similarly, on a circular arc with the radius of displacement distance rB which corresponds to a detection value VB from the center B of the coil 16b. Therefore, the center Om is either of these two intersected points of the circular arcs (Xm , Ym ) and (X'm , Y'm ). Furthermore, a circular arc with the radius rC from the detection value Vc of the coil 16c, and the coordinates (Xm , Ym ) of the center Om can be identified. Statistics processing is performed by using the fourth detection value VD.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane (tire traveling gantry crane, transfer crane, etc.),
The present invention relates to a continuous position detection / control device used for automatic traveling / positioning of a moving body such as an automatic traveling vehicle, an AGV, a transport vehicle, a forklift and the like.

[0002]

2. Description of the Related Art A conventional automatic running / positioning method is shown in FIG.
8 and FIG. 19 are typical examples.

One of the typical examples is a guide line system as shown in FIG. 18, in which a guide line a continuously arranged on a track is read by a sensor c installed on a traveling vehicle b, and the guide line a is read from the guide line a. This is a method of traveling while correcting the deviation. Common types of the guide wire a include (I) a wire or tape made of a conductor, (II) a magnetic tape, (III) a painted wire capable of distinguishing brightness and color, and the like. The general sensors c used in combination with the guide wire a include (I) an eddy current sensor, (II) a magnetic sensor, (III) a light reflection sensor, and (IV) a CCD camera. The line a and the sensor c are used in combination. As a specific combination, as shown in FIG. 18, a combination of paint or a magnetic material wire or a mark line (guide line a) made of a magnetic material α and a sensor c made of a magnetic sensor or a CCD camera is used. And a combination of a mark line (induction line a) composed of a conductor β disposed on or below a road surface and a sensor c composed of an eddy current sensor.

Another typical example is a discontinuous mark system using a combination of a discontinuous mark and a running integrator as shown in FIG. ) M, the reference mark m is detected by a sensor c installed on the traveling vehicle b, and an intermediate position thereof is estimated by a traveling integrator d or the like. In general, reference marks m include: (I) a transponder which starts self-position information through radio waves; (II) a magnetic plate; (III) a conductor (magnetic material); and (IV) a geometric mark (reflection). And the sensor c used in combination with the reference mark m are (I) a radio wave / transmitting / receiving antenna, (II) a magnetic sensor, (III) an eddy current sensor, and ( IV) Optical sensor (V) CCD camera, etc., which are used in combination with reference mark m and sensor c.

[0005]

Generally, in order to perform positioning and automatic traveling, accurate detection of the position of the guide,
Although it is necessary to detect the position in the traveling direction, the above-described conventional method has the following problems. (1) In the case of the guide line system shown in FIG. 18, since the guide line a is continuous (uniform in the running direction), position detection in the running direction is impossible. (2) In the case of the discontinuous mark method shown in FIG. 19, both the traveling direction position and the displacement can be detected, but (a) the detection accuracy of the reference point is not good due to the shape effect of the reference mark m. . (B) It is difficult to determine the traveling direction of a mark having a small shape effect. (C) Since the camera performs two-dimensional detection, these problems can be solved. However, optical sensors are generally susceptible to disturbance and have a problem of lack of reliability. (3) The position detection sensor also has the following problems. (A) In the case of an eddy current or magnetic sensor The directionality is difficult to identify. Further, when a material of the same quality as the mark is present in the vicinity, it is difficult to determine the same. (B) In the case of an optical sensor or a CCD camera Since the light is intuitive, it is not impossible to identify the direction if the shape of the mark is devised, but it is easily affected by sunlight, rain, dust, etc. outdoors. Not reliable. (4) In the case of the continuous guidance system, there are many problems such as (a) high installation cost and (b) maintenance is troublesome. (5) On the other hand, in the discontinuous mark method, it is difficult to maintain accuracy when running between marks.

SUMMARY OF THE INVENTION The present invention has been made in view of such various problems, and has as its object to provide the above-described discontinuous reference marks (position marks) for guidance and movement of moving vehicles such as traveling vehicles. To enable continuous and two-dimensional accurate detection of both the relative position with respect to the body and the position in the running direction, and to enable smooth positioning and automatic running control of the moving body. It is an object of the present invention to provide a continuous position detection and control device for a moving body that satisfies both of them.

[0007]

In order to achieve this object, the present invention provides: (1) a position mark on a track and a position mark detecting means on a moving body; A sensor head comprising a plurality of position detection sensors having the same kind of function as a set and a plurality of position detection sensors; and a calculation device for identifying the mark position by integrating and calculating signals from the plurality of position detection sensors. It is configured to (2) Further, the position detection sensor is formed of a coil body, and the position mark is formed of a conductive plate such as a metal, and the position is detected from a change value of an eddy current detected by the position detection sensor. It is configured as follows. (3) Further, the position mark plate made of the conductor plate is formed in a disk shape. (4) Further, the number of position detection coils provided in the sensor head is set larger than the geometrically necessary number, and the position detection accuracy is increased by using a redundant signal. (5) The sensor head case, on which the sensor head is mounted, is supported on a support frame on a moving body so as to be vertically movable and grounded via rotatable wheels, whereby the sensor head travels on the moving body. Is configured to follow. (6) Further, the sensor head case is supported on the support frame via a spring so as to be maintained at a fixed distance from the ground surface. (7) Further, the arithmetic unit is provided with an integrating arithmetic section for integrating the number of position marks and integrating the deviation between the nearby position mark reference point and the sensor head reference point. (8) The arithmetic unit further includes an arithmetic unit that compares the arithmetic value of the integration arithmetic unit with an integrated value from the encoder information indicating the wheel rotation amount detection value. (9) In addition, a plurality of the sensor heads are provided in combination. (10) In addition, the plurality of sensor heads are arranged at an appropriate distance from the position mark so that any one of the sensor heads can always detect the position mark. (11) The arithmetic unit is provided with an arithmetic unit for performing statistical processing arithmetic such as averaging errors due to sensor characteristics when the sensor head for position detection is switched. (12) In addition, the plurality of sensor heads are arranged at positions that can be simultaneously detected with respect to the position mark, and are configured to detect a traveling direction of the moving body. (13) In addition, the moving body is a transfer crane,
It is composed of a gantry crane, an automatic traveling vehicle, an AGV, a transport vehicle or a forklift.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] FIG. 1 is a perspective view showing an embodiment of a tire traveling type gantry crane 1 provided with a continuous position detection / control device according to the present invention. The tire-traveling gantry crane 1 of this example is provided with a trolley 3 traversing on a portal frame 2 in the y direction, a container 4 suspended below the trolley 3, and an upper part of the container 4. And a spreader 5 that moves up and down in the vertical direction, and is mounted on each of a pair of drive unit frames 6a, 6b and 6c, 6d disposed on both left and right portions of the lower part of the gate-shaped frame 2. Motors 7a, 7b and 7c, 7d, driving wheels 8a, 8b, 8c, 8d, which are rotationally driven by these driving motors 7a to 7d, respectively, and driven wheels 9a, 9b,
9c and 9d make it possible to travel in the x direction.

A control unit storage unit 10 is provided at an upper end portion of the frame 2, and inside the control unit storage unit 10, the crane 1 travels in the x direction.
A control device (not shown) for traversing the trolley 3 in the y-direction, moving the spreader 5 up and down, vertically attaching and detaching the container 4, and automatically operating these components is stored.

Further, between the driving wheel 8a and the driven wheel 9a,
Between the driven wheel 9a and the driven wheel 9b, the driven wheel 9b and the driving wheel 8
b, a position detection sensor (sensor heads 14a, 14b, described later) for detecting the position mark plate 11a.
14c) are mounted respectively. In addition, one sensor head case (not shown in FIG. 1) for accommodating a position detection sensor for detecting the position mark plate 11b at an appropriate position on the side of the drive wheels 8c and 8d and the driven wheels 9c and 9d. Is installed. In FIG. 1, 13
Is a traveling road surface on which the crane 1 travels. The above-mentioned position mark plate 11a is made of a good electric conductor (metal or the like) and is arranged on the traveling road surface 13 at an equal pitch.

In this specification, the drive motor 7
a to 7d, drive wheels 8a to 8d, sensor head case 12
The portion composed of a to 12c and the like is referred to as a “traveling drive unit”. Two sets of the “traveling drive units” are provided on both left and right leg ends of the gate-shaped frame 2 and are respectively referred to as a travel drive unit R ₁ and a travel drive unit R ₂ . Both traveling drive units R ₁ and R ₂ have the same configuration.

[0012] Figure 2, there is shown a sensor head 14 which is disposed traveling drive unit R _1, sensor head 14 used in this embodiment, in FIG. 2 (A), (C) and (D) As shown, for example, four position detecting coils 16a and 16 having the same function are provided in the sensor head casing 15 with a flange.
b, 16c, 16d and one excitation coil 17. And this sensor head 14
As shown in FIG. 2B, the above-described sensor head case 1
The flange portions 15a are fixed by screws 18 while being accommodated and arranged in the respective 2a to 12c, and the sensor head cases 12a to 12c are attached to the frame 2 side. That is, the holder 20 is connected to the support frame 19 connected to the drive unit frame 6a of the crane 1 or the like.
The sensor head cases 12a to 12c are vertically movably mounted on a rod 22 which is constantly urged downward by a spring 21 housed in the holder 20.
Although not shown, the rod 22 and the holder 20 are fixed in a state where rotation is prevented by a rotation preventing mechanism (not shown). And each sensor head case 1
The wheels 2a to 12c are placed on the traveling road surface 13 via a plurality of rotatable lift stabilizing auxiliary wheels 23a and 23b configured as casters, and are free to move in the vertical direction.

FIG. 3 shows an example of a signal processing circuit of the sensor head 14. As shown in FIG. As shown in FIG. 3, the output signal of the oscillator 25 is amplified by the amplifier 26, and the amplified AC voltage is supplied to the excitation coil 17 of the sensor head 14. On the other hand, the position detecting coil 16a of the sensor head 14 (the same applies to 16b to 16d)
The signal passes through an amplifier 27a and a detector 28a sequentially, and is connected to an arithmetic unit (CPU) 31 via an analog / digital converter (A / D converter) 29a and a connection interface (I / F) 30. Further, the above-described arithmetic unit 31 is connected to the sensor signal processor (A) via the external connection interface 32.
NL) 33. A processing circuit composed of circuit elements from the oscillator 25 to the external connection interface 32 is referred to as a detection value processing device 34 (see FIG. 3).

As shown in FIG. 4, a plurality of the above-described detection value processing devices 34 are provided for each of the sensor heads 14a, 14b, 14c and 14d (four in this example, 34a and 34d).
b, 34c, 34d). As shown in FIG. 3, each of the detection value processing devices 34a to 34d is connected to a sensor signal processor 33 via an external connection interface 32 or the like. The output signal from the sensor signal processor 33 is configured to be supplied to the control device (CONT) 35 as a control signal. In FIG. 4, (Δx, Δy) is a two-dimensional displacement detection value, and (Δx, Δy) is (Δx, Δy).
θ, Δθ ′) is the inclination of the crane 1 during traveling.

FIG. 5 shows the structure of lift stabilizing auxiliary wheels 23a and 23b which are caster wheels. As shown in FIG. 5, toothed pulleys 37 are provided on the lift stabilizing auxiliary wheels 23a and 23b, and are connected to a rotation transmitting pulley 39 by a belt. Further, the rotation transmission pulley 39 is connected to a bevel gear 41 via a shaft 40, and is rotatable together with the rotation transmission pulley 39. The bevel gear 41 is meshed with a bevel gear 44 attached to an input shaft 43 of an encoder 42.

FIG. 6 shows an input circuit to which two encoders 42 are added, and two encoders 42a and 42b are provided.
Are integrated by the pulse counters 46a and 46b, respectively, and are connected to the arithmetic unit 31 via an interface (I / I) 47. The other circuit configuration is the same as that shown in FIG.

FIG. 7 (A), (B) and (C), (14 a to 14 c in three cases) arrangement of sensor head 14 which is disposed on the side of the travel driving portion R ₁ indicates a is there. As shown in FIG. 7A, the sensor heads 14a to 14c are arranged at positions shifted by an equal ratio to an integral multiple of the pitch of the position mark plate 11a or at an integral multiple. That is,
In this example, as shown in FIG. 7B, assuming that the length readable by one sensor head 14 is, for example, 0.5 m, the sensor head 14b and the sensor head 14c have a pitch between the adjacent position mark plates 11a. For 1m,
It is arranged so as to be shifted by 2.5 m (2.5 × p, p is a pitch). Further, the sensor head 14a is at a position of 6 m (6 × p) with respect to the sensor head 14c, and
It is arranged at a position of 3.5 m (3.5 × p) with respect to the sensor head 14b.

Meanwhile, on the side of the travel driving portion R ₂ of the other side,
As shown in FIG. 7A, at equal pitches (the position mark plate 1).
A position mark plate 11b arranged at an integer value of the pitch of 1a, for example, 6 m), and a sensor head 14d arranged at a position corresponding to any of the sensor heads 14a to 14c (here, a position corresponding to the sensor head 14b). And each is provided.

The operation and effect of the above-described device will be described below. [1] Basic Principle for Detecting Position Mark Plate In FIG. 8, when an alternating current is supplied to the exciting coil 17 of the sensor head 14, if the position mark plate 11 is a conductor, an eddy current is generated therein. . This eddy current is detected by the position detecting coil 16 (actually, it is detected as a change in AC impedance). The detected eddy current is processed by the detector 28, and a voltage signal corresponding to the magnitude is output from the detector 28. The strength of the eddy current is determined by determining one of conductors 50 and 51 serving as position mark plates (a special one of position mark plate 11) and one of position detection coils 16 (position detection coils 16a to 16d). And the height h. Note that 50 is an infinitely long conductor, and 51 is a large conductor.

FIGS. 8A and 8B show the relationship between the conductor 50 (a special form of the position mark plate 11) and the detected value (voltage) which are infinitely long in the y direction in order to show the characteristic of only the distance. The relationship and the relationship between the very large conductor 51 (a huge component of the position mark plate 11 and the distance component is saturated, so that the characteristic of only the height h is known) and the position detecting coil 16 are conceptually shown. It is shown. Therefore, if the distance 1 is fixed, the height h of the position detecting coil 16 and the conductors 50 and 51 can be known. If the height h is constant, the distance 1 between the conductors 50 and 51 and the position detecting coil 16 can be known.

The purpose here is to know the deviation of the distance between the position mark plate 11 and the sensor head 14. Since the sensor head case 12 is pressed by the spring 21 in a state in which the lift stabilizing auxiliary wheels 23a and 23b are in contact with the traveling road surface 13, the sensor head 14 is moved irrespective of the vertical movement of the crane body frame 2 ( Consequently, it can be kept at a fixed distance from the position mark plate 11).

[0022] The sensor head case 12 is the caster wheels (auxiliary wheels 23a, 23b) regardless of the traveling direction of the traveling drive unit R ₁ and the traveling drive unit R ₂ to be held in, and can move unconstrained Become. That is, the position detecting coil 16 can detect the magnitude of the eddy current generated by the exciting coil 17 as a change in distance.

[2] Shape Effect of Position Mark Plate FIG. 9 shows the shape effect of the position mark plate 11. With the above-described operation, the distance between one position detection coil 16 and one position mark plate 11 and the position mark plate 11 can be known. However, the height h is constant. However, an infinitely long or extremely large position mark plate 11 is not realistic.

FIG. 9A shows the relationship between the rectangular mark plate 60 and the sensor output (however, the height h is assumed to be constant). In this case, when the position detecting coil 16-I passes through the center of the rectangular mark plate 60, a larger signal is obtained. Therefore, for example, from the position detection coil 16-I passing through the center of the rectangular mark plate 60 and the position detection coil 16-H passing outside the rectangular mark plate 60, the respective coil centers and the center of the mark plate 60 are The same output is obtained despite the difference in the x direction in the x direction. That is, it indicates that it is difficult to detect a two-dimensional displacement only with the output voltage of the position detection coil.

FIG. 9B shows characteristics in the case of the circular mark plate 61. Also in this case, when the characteristics are represented by xy coordinates from the center of the circular mark plate 61, the same result as that of the rectangular mark plate 60 is obtained. However, when represented by the distance r from the center of the circular mark plate 61, the circular coil has no directionality (the same if the overlap is the same), so the position detecting coil 16-I.
And 16-H have the same properties as a function of distance from the center. When a non-directional mark plate (for example, a disk) and a non-directional detection exciting coil (for example, a circular coil) are combined, the relationship between the center of the mark plate and the position detection coil becomes the same. For reference, even if the plane has directionality,
It is noted that the same effect can be obtained by devising the thickness.

[3] By using a plurality of position detecting coils
Displacement detection For simplicity of explanation, four positions as shown in FIG.
Make the detection coils 16a, 16b, 16c, 16d orthogonal.
Consider the case where they are arranged on different axes. In this case, for position detection
The detected value of the coil 16a is V_A, Position detecting coil 16b
Is the detected value of V_BAnd the detected value of the position detecting coil 16c is V
_C, The detected value of the position detecting coil 16d is V_DThen
The center of the circular mark plate 61 (mark plate 11) corresponds to the center.
Deviation distance r_AOn a circle whose radius is
Center A of coil 16a). Similarly, the detection value V_BFrom the circle
The center of the shape mark plate 61 has a radius r centered on B._BCircle of
It's above. That is, the center O of the circular mark plate 61_mHako
The intersection of these two circles (X _m, Y_m) Or
(X '_m, Y '_m). Further, the detection value V
_CTherefore, the center of the circular mark plate 61 is centered on the point C.
Radius r_CIt's above. This allows the center O_mCoordinates
(X_m, Y_m) Can be identified. Therefore, theoretically three
Circular marker with position detection coils 16a, 16b, 16c
That the center of the mark plate 11 composed of the mark plate 61 can be identified.
However, in practice, it depends on the characteristics of each position detection coil, etc.
Of the fourth position detecting coil 16d
Value V_D= R_D(Values obtained from redundant signals)
Performs total processing.

When these are generalized and shown by mathematical expressions,

[Number 1] center _{A (X a, Y a)} , a circle of radius _{r a: (X-X a} ) 2 + (Y-Y a) 2 = Y a 2 ......... (1) center B (X _b , Y _b), of radius r _{b ^{circle: (X-X b) 2}} + (Y-Y b) 2 = Y b 2 ......... (2) the center _{C (X c, Y c)} , the radius r _{c ^{yen: (X-X c) 2}} + (Y-Y c) 2 = Y c 2 ......... (3) center _{D (X d, Y d)} , a circle of radius _{r d: (X-X d} ) 2 + (Y−Y _d ) ² = Y _d ² (4) From these two equations, the following 12 coordinates of the intersection are obtained.

## EQU2 ## O _mi , _j (X _i , _j , Y _i , _j ) i, j = 1 to 4 (5) where i ≠ j are the same points if there is no error. because there is,

(Equation 3) And averaging these,

(Equation 4) X _m and Y _m are obtained by If there is no solution in the above, the eddy current value is not sufficiently large (for example, the detection coil is too far from the mark plate) and the error is large, so that it is processed as erroneous reading.

[4] Continuous Reading of Discontinuous Marks (1) Basic Principle (See FIG. 11) When the sensor head 14-1 approaches a certain distance from the mark plate 11 / n (the nth mark plate 11), the sensor head 14-1 Detection becomes possible (see the solid line state C ₀ in FIG. 11). In addition, detection is possible until a similar distance is left (FIG. 1).
See a solid line state C ₁ in 1). Here, during this period in the range (distance) and l _m.

First, assuming that the sensor head 14-1 advances rightward (in the direction of the arrow), the second sensor head 14-2 is located at a distance l _m behind (left) the sensor head 14-1.
Is arranged, the sensor head 14-1 is connected to the mark plate 11 / n.
When the sensor head 14-2 moves away from the mark plate 11 / n, the sensor head 14-2 approaches the mark plate 11 / n to be in a detectable state. At this time, the used head is switched to 14-2. Further, when the sensor head 14-2 advances by a distance 1 _m , the sensor head 14-2
-1 state C ₂ becomes as shown in FIG. 11, the mark plate 11 / n
+1 can be detected. At this time, the used head is switched to the sensor head 14-1.

If the reading interval of the sensor head 14 is l _m , the mark plate pitch is p _m , and the number of connected sensor heads 14 is n,

P _m = n × l _m ... (8) Continuous reading is enabled by the relationship defined by (8).

(2) Development of Arrangement In the above, the sensor heads 14 are arranged at a pitch of 1 _m . However, if the relationship of Expression (8) is maintained, the arrangement of the sensor heads 14 is as follows.

[Outside 1] Becomes Figure 7 (B) in the number of sensor heads n = 2 or reading distance l _m = 0.5 mark plates distance _{P = n × l m = 2} × 0.5 = 1m sensor head distance k ₁ = 5 l ' _m = k ₁ × l ′ _m = 5 × 0.5 = 2.5 m, and by alternately utilizing the sensor heads 14 b and 14 c, the mark plate 11 placed every 1 m
The position a (deviation from the sensor head 14) can be detected continuously. This calculation is based on the signals (Δx ₂ , Δy ₂ ) (Δx ₃ , Δx ₂ ) of the sensor head 14 b, the detection value processing device 34 b, the sensor head 14 c, and the detection value processing device 34 c.
y ₃ ) using the sensor signal processor 33.

(3) Detection of angular displacement (see FIG. 12) For the corresponding sensor head 14c

(6) l _m = k · p (9) k: integer p: mark plate pitch When the sensor heads 14a are arranged such that: 14a and 14c are simultaneously detectable. FIG. 12 shows this state. At this time, the angle shift is

(Equation 7) Can be calculated as This calculation is performed by the sensor signal processor 33 using output signals from the sensor head 14a and the detection value processing device 34a and output signals from the sensor head 14c and the detection value processing device 34c.

[5] Output and Correction of Crane Deviation (Displacement) (1) Traveling and Traversing Displacement The sensor signal processor 33 selects a detector processing device necessary for detection, and calculates an angle displacement to calculate the crane deviation. The travel (x direction), traversing (y direction), and angular deviation of No. 1 are output to the control device 35.

(2) Crane Angle Deviation and Correction The crane angle deviation, that is, the skew Δθ _sk is detected by:
A sensor head 14d on traveling drive unit R _2, for example using the sensor head 14b on the traveling drive unit R _1, determined by the following equation (12) (see FIG. 13).

(Equation 8) As described above, the displacement in the traveling direction and the displacement in the traverse direction of the crane can be continuously detected. An angle shift can be detected at a required pitch (timing). Further, the skew of the crane can be detected between the required pitches.

[6] Control Method From the sensor signal processor 33, a deviation Δy from a line (traveling line: x-axis) continuously connecting the mark plates 11a and a positional deviation from the mark plate 11a on the traveling line. Δx, the inclination Δθ of the traveling drive unit R ₁ with respect to the x-axis, and the traveling drive unit R
₁ and the traveling displacement of the drive unit R ₂ (slope) [Delta] [theta] _sk is output.

(1) Correction of Traveling Deviation The correction amount in the traveling direction can be easily calculated by the following equation (12), for example.

Y _c (t) = f (Δy (t)) (12) y _c (t): To the drive motor of the control system at time t Output f: arithmetic function. In the simplest case, the proportional constant Δy (t) is the deviation amount from the x-axis at the time t. Correction becomes possible.

(2) Positioning in x direction

X _c (t) = g (Δx (t)) − x _a (13) x _c (t): control system output at time t g: operation function [Delta] x (t): the deviation of the position mark plate 11a at time t x _a: deviation from the center position mark plate 11a of the stop position

X = ∫Δ (t) dt + δ · n · p (14) n: Number of passed position mark plates p: Position mark plate pitch δ: +1 Positive direction running count δ: -1 Negative direction running count The running distance is calculated by equation (14). Therefore, the positioning to the target position is performed at the position to be stopped, for example, x _a =
A traveling drive unit formula (13) R ₁ for performing control such deviation Δx on the position mark plate 11a (t) is zero as 0 is stopped at a position represented by the center of the place mark plate 11a.

[0038] (3) displacement correction should be noted that the traveling drive unit R ₂ at this time performs the follow-up to control the traveling drive unit R _1. As an example, a method using the tilt angle Δθ will be described.

Equation 12] _{θ c (t) = h (} Δθ (t)) .................................... (15) θ c (t): travel drive unit at time t R ₂ to the drive motor control output of h: calculation function [Delta] [theta] (t): when the slope for example [Delta] [theta] (t) is shifted in the positive direction with respect to the traveling drive unit x-axis of R ₁ at time t, the traveling drive unit R ₂
Drive motor speed is reduced. Conversely [Delta] [theta] (t) is the drive motor of the traveling drive unit R ₂ and shifts in the negative direction is accelerated.
Thus, the crane 1 can travel while maintaining a constant skew angle.

(4) Skew angle holding stop At the position where the skew angle is to be stopped, position mark plates 11a and 11b are laid on both the traveling drive units R ₁ and R ₂ . By positioning the mark plate at the time of stopping, the crane can be stopped with the skew angle of the crane set to a target angle (usually adjusted to the y-axis direction, Δθ _SR = 0).

(Equation 13)

(5) Smoothness of operation Since discontinuous marks are used in this method, errors in laying the position mark plates 11a and 11b and the sensor heads 14a to 14b
A 14d-specific error or the like is assumed. Therefore, there is a possibility that the detection value may suddenly shift when the sensor heads 14a to 14d are switched. As a result, if the control amount also changes suddenly, the smoothness of operation is impaired (see FIG. 14). Therefore, some contrivance is required for the sudden change that occurs when the sensor head is switched. For example, it is known that improvement can be expected by averaging the characteristics of the sensor heads 14a to 14d at the time of switching. Alternatively, although not described in detail, it is also known that improvement can be achieved by introducing an idea of fuzzy control. In any case, smooth controllability can be obtained by mutually correcting the characteristic change between the used sensor heads 14a to 14d.

(6) Checking the detected value As described above, the position of the sensor head from the position mark plate can be continuously detected. However, the encoder is required to cope with unintended disturbances (such as a defective mark plate). The calculation from 42 is also used. That is, for the sake of simplicity, considering only the x direction,

Equation 14] x = ∫Δx (t) dt + δ · n · p ................................. (17) x c = ∫k E · D E · n E · p · cos θdt + δ · n _{· p ... (18) D E} : lift stable auxiliary wheels 23a, 23b of diameter n _E: lift stable auxiliary wheels 23a, the rotation amount of 23b p: per revolution of the encoder 42 pulses k _E: reduction (increase) Speed ratio θ: attitude of sensor at time t

(Equation 15)Can be used to calculate two traveling distances (note that the above equation (1)
X used in 9)_ca, X _cbFor the details, see FIG. 15).
Therefore, let x be x_cAbnormal against disturbance while checking with
Can be detected.

[Equation 16] x {x _c } → OK

Second Embodiment FIGS. 16 and 17 show an embodiment in which the present invention is applied to an automatic traveling vehicle 70. FIG. Three sensor heads 14a, 14b, and 14c are mounted on the bottom surface of the automatic traveling vehicle 70 in a row at appropriate intervals in the traveling direction. The position mark plates 11 are arranged in a line on the traveling path of the vehicle 70 at intervals. Other configurations are provided similarly to the first embodiment.

Also in this case, the three sensor heads 14
As for the gantry crane 1, a, 14b and 14c can read the position of the mark plate 11. Accordingly, by performing steering according to the deviation, unmanned traveling or the like can be realized.

The direction of the automatic traveling vehicle 70 often changes in a complicated manner, and the position mark plate 11 may not always be read. In this case, it is of course possible to utilize the value obtained by integrating the signals from the encoder 42 (see FIG. 5). Furthermore, in order to make the system convenient, a system using one sensor head and using the encoder 42 in an undetectable area in the middle between the position mark plates 11 can be applied (however, smooth operation is impaired). ). Also in this case, the position (deviation) can be detected two-dimensionally in the vicinity of the position mark plate 11, which is effective for flat free running.

The configuration and operation of the apparatus for detecting and controlling the continuous position of a moving object according to the present invention as described above are summarized as follows. First, the sensor heads 14a to 14
c, a plurality of position detection sensors (position detection coil 16
a to 16d), by monitoring and detecting the position mark (position mark plate 11a), the reference point of the position mark is calculated as a relative coordinate from the reference position of the sensor group (position detection coils 16a to 16d group). . Further, by using an isotropic circular plate as a position mark (circular mark plate 61), the approach direction of the moving body to the position mark is detected when calculating as relative coordinates from the reference position of the sensor group.
In addition, a conductive disk (circular mark plate 61) is used as a position mark plate, and an eddy current sensor (excitation coil 17 and position detection coils 16a to 16d) having a small characteristic change with respect to weather factors is used as a sensor. 14a-14
Use c). Also, a plurality of sensor heads, each of which is a unit of a sensor group, are appropriately shifted and arranged so that any one of the sensors is always at the position mark plate detection position. Further, by making the sensor head cases 12a to 12c vertically movable with respect to the moving body or further grounding with a freely rotating wheel via a spring 21 (see FIG. 2B), a measurement error due to a lift-up movement of the eddy current sensor. To reduce the effects of Further, the movement position detected by the arithmetic unit 31 (see FIG. 3) is mutually checked with the traveling detection means by the encoder 42, and a discontinuous signal when the sensor head for detecting the position mark is switched to another individual is output. Statistical processing and continuous coupling ensure detection accuracy and reliability. In addition, by combining these, it is possible to perform two-dimensional and continuous position detection and smoothly move the moving body.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes can be made based on the technical idea of the present invention. For example, the present invention provides various types of transfer cranes, AGs other than gantry cranes and automatic traveling vehicles.
V, a transport vehicle, a forklift, or the like can be appropriately applied.

[0047]

According to the present invention as described above, the following effects can be obtained by the matters described in the claims. (1) A position mark (discontinuous mark plate) with excellent detection stability, a sensor head consisting of a group of multiple position detection sensors with the same function, and signals from these multiple position detection sensors are integrated. The provision of the arithmetic unit for calculating and identifying the mark position enables accurate detection of the displacement of the moving body with respect to the mark position. (2) Since the position mark (position mark plate) may be discontinuous, replacement is easy and maintainability is improved. (3) The position mark may be an ordinary conductor, so that the installation cost is low. In addition, compared to a magnet or the like, a system that is less likely to adhere to dust and has excellent weather resistance and good durability can be provided. (4) By using a plurality of eddy current sensors (position detecting coils), two-dimensional displacement detection (Δx, Δy) can be continuously detected. (5) By providing a plurality of sensor heads in the traveling direction of the traveling drive unit, the inclination (Δ
θ) can be calculated and the speed of the corresponding travel drive can be controlled,
Stable traveling as a crane becomes possible. (6) By using a sensor head and a mark plate as necessary for the left and right traveling drive units of the moving body, it is possible to perform position control (correction of skew angle skew at the time of stopping) by setting a skew angle to a predetermined value. Become. (7) The reliability can be improved by combining the detection value obtained from the position detection sensor with another type of detection value processing device. (8) Accurate positioning of the moving body and smooth automatic traveling operation can be achieved by taking the above into account.

[Brief description of the drawings]

FIG. 1 is a perspective view of a tire traveling gantry crane provided with a continuous position detection / control device according to a first embodiment of the present invention.

FIGS. 2A and 2B are views for explaining a sensor head used in an embodiment of the present invention, wherein FIG. 2A is a perspective view of the sensor head, FIG.
(C) is a bottom view of the sensor head, and (D) is a cross-sectional view of the sensor head.

FIG. 3 is a block diagram illustrating a configuration of a detection processing device for a position signal detected by a sensor head.

FIG. 4 is a block diagram showing a configuration of a control device including the device of FIG.

FIG. 5 is a perspective view showing a configuration example of a caster wheel for a sensor head.

FIG. 6 is a block diagram of a detection processing device formed by adding an encoder input circuit to the circuit of FIG. 3;

FIGS. 7A and 7B are views for explaining an arrangement state of a sensor head, wherein FIG. 7A is a plan view of a tire traveling type gantry crane, FIG. 7B is a plan view of a traveling drive unit on one side of the crane, FIG. (C) is an explanatory view showing the state of attachment of the sensor head to the one traveling drive unit.

8A and 8B show two experimental examples and graphs showing the detection characteristics of the eddy current sensor, and FIG. 8A shows an arrangement relationship between the sensor head and a mark plate made of a conductor infinitely long in the y direction. (B) is a graph showing a relationship between a distance between a sensor head and a mark plate and a detection voltage, and (C) is a diagram showing an arrangement relationship between the sensor head and a mark plate made of a very large conductor. (D) is a graph showing the relationship between the distance between the sensor head and the rectangular mark plate and the detection voltage.

9A and 9B show two experimental examples and graphs showing the effect of the shape of the mark plate, wherein FIG. 9A is an explanatory diagram of a sensor output when a rectangular mark plate is used, and FIG. It is explanatory drawing of the sensor output at the time of using.

FIG. 10 is an explanatory diagram of the principle of detecting the deviation between the mark plate and the center of the sensor head.

FIG. 11 is an explanatory diagram of the principle of continuous alternation detection of a discontinuous mark plate.

FIG. 12 is an explanatory diagram of a principle of detecting a shift angle between an arrangement axis of a mark plate and a traveling direction of a moving body.

FIG. 13 is an explanatory diagram of a principle of detecting a skew of a moving body with respect to an arrangement axis of a mark plate.

FIG. 14 is an explanatory diagram of a principle of correcting a sudden change in a sensor detection value when a detection sensor is switched.

FIG. 15 is a diagram showing the concept of numerical elements used in an equation for calculating the attitude of a sensor.

FIG. 16 is a side view of an automatic traveling vehicle provided with a continuous position detection / control device according to a second embodiment of the present invention.

FIG. 17 is a plan view of the automatic traveling vehicle of FIG.

FIG. 18 is a perspective view for explaining a conventional guide line type positioning / automatic traveling method.

FIG. 19 is a perspective view illustrating a conventional discontinuous mark type positioning / automatic traveling method.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 tire traveling type gantry crane 2 gate type frame 3 trolley 6 a to 6 d driving unit frame 8 a to 8 d driving wheel 9 a to 9 d driven wheel 10 control unit storage unit 11, 11 a, 11 b position mark plate 12 a to 12 d sensor head case 13 traveling Road surface 14a to 14d Sensor head 16, 16a to 16d, 16-I, 16-H Detection sensor 17 Excitation coil 23 Lift stabilization auxiliary wheel 20 Holder 21 Spring 22 Rod 25 Oscillator 26, 27a to 27b Amplifier 28a to 28d Detector 29a-29d Analog-to-digital converter 30 Connection interface 31 Arithmetic unit 32 External connection interface 33 Sensor signal processor 34, 34a-34d Detected value processor 35 Controller 42, 42a, 42b Encoder 46a, 46b Pulse counter 4 7 interface 50 infinitely long conductor 51 large conductor 60 rectangular mark plate 61 circular mark plate 70 automatically traveling vehicle R ₁ right traveling drive unit R ₂ left travel drive unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeo Kamimura 2-1-1 Shinama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. No.1 Inside Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd.

Claims (13)

[Claims] 1. A sensor head comprising a position mark on a track and a position mark detecting means on a moving body, wherein the position mark detecting means is provided by assembling a plurality of position detecting sensors having the same function. And a calculating device for integrating the signals of the plurality of position detecting sensors to identify the mark position. . 2. The position detection sensor is formed of a coil body, and the position mark is formed of a conductive plate such as a metal, and the position is detected from a change value of an eddy current detected by the position detection sensor. The continuous position detection / control device for a moving body according to claim 1, wherein the device is configured as described above. 3. The continuous position detecting / controlling device for a moving body according to claim 2, wherein the position mark plate made of the conductive plate is formed in a disk shape. 4. The apparatus according to claim 2, wherein the number of position detecting coils provided in the sensor head is more than the geometrically necessary number, and the position detection accuracy is increased by using a redundant signal. 3. The continuous position detection and control device for a moving object according to 3. 5. A sensor head case on which the sensor head is mounted is movably supported on a support frame on a moving body and is grounded via rotatable wheels, whereby the sensor head travels on the moving body. The continuous position detection and control device for a moving object according to claim 2, wherein the continuous position detection / control device according to claim 2 or 3 is configured to follow. 6. The continuous position detecting and controlling device for a moving body according to claim 5, wherein the sensor head case is supported on the supporting frame via a spring so as to be maintained at a fixed distance from the grounding surface. . 7. The calculation device according to claim 2, wherein the calculation device includes an integration calculation unit that performs integration of the number of position marks and integration of a deviation between a reference mark of a nearby position mark and a reference point of the sensor head. 3. The continuous position detection and control device for a moving object according to 3. 8. The arithmetic unit according to claim 1, further comprising an arithmetic unit for comparing the arithmetic value of said integration arithmetic unit with an integrated value from encoder information indicating a wheel rotation amount detection value. 8. The continuous position detection and control device for a moving object according to 7. 9. The continuous position detecting / controlling apparatus for a moving body according to claim 1, wherein a plurality of the sensor heads are provided in combination. 10. The apparatus according to claim 1, wherein the plurality of sensor heads are arranged at an appropriate distance from the position mark so that any one of the sensor heads can detect the position mark. 10. A continuous position detection and control device for a moving object according to claim 9. 11. An arithmetic unit for performing a statistical processing operation such as averaging an error due to a sensor characteristic when switching the sensor head for position detection. The continuous position detection and control device for a moving object according to 9 or 10. 12. The apparatus according to claim 9, wherein the plurality of sensor heads are arranged at positions that can be simultaneously detected with respect to the position mark, and are configured to detect a traveling direction of the moving body. A continuous position detection / control device for a moving object according to the above. 13. A transfer crane, comprising:
10. The continuous position detection and control device for a moving object according to claim 9, wherein the device is constituted by a gantry crane, an automatic traveling vehicle, an AGV, a transport vehicle, or a forklift.