JP2018177002A - Unmanned transport truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an unmanned transport truck capable of moving along a guidepath without requiring field adjustment.SOLUTION: In an unmanned transport truck 10 including an automatic driving operation part 14 for moving a truck part 12 along a guidepath 13 of a floor surface 11, the automatic driving operation part 14 includes truck deviation detection means 15 for detecting a truck deviation distance X with respect to the guidepath 13 of the truck part 12 and truck driving control means 16 for moving the truck part 12 along the guidepath 13 while correcting the truck deviation distance X. The truck driving control menas 16 includes a truck movement command unit 19 for outputting a rotation driving signal by which the rotation of driving wheels 17, 18 of the truck part 12 is controlled, a track correction command unit 20 for calculating the rotation correction amount of the driving wheels 17, 18 required for the correction of the truck deviation distance X by the sliding mode control and outputting it as a rotation correction signal, and a driving source control unit 23 for inputting rotation command signals including a combination of a rotation driving signal and a rotation correction signal into rotation driving sources 21, 22 of the driving wheels 17, 18.SELECTED DRAWING: Figure 2

Description

The present invention relates to an unmanned transport carriage of a magnetic induction type, and in particular, no on-site adjustment is required, and the floor surface is not affected by uncertain factors such as weight change of load and floor condition change. The present invention relates to an unmanned transfer carriage that moves along a guideway set in

On the floor surface on which the magnetic guidance type unmanned transfer carriage moves, guide paths consisting of magnetic tapes for guiding the movement of the unmanned transfer carriage are laid, and on the left and right sides of the guide path, for example, A plurality of magnetic markers made of magnetic tape for giving instructions such as reverse travel, turning, stop, acceleration and deceleration are arranged. On the other hand, in the lower part of the unmanned transfer carriage, in order to detect the magnetic tape constituting the guide path, the first magnetic sensors are arranged at predetermined pitches on both sides in the width direction centering on the center in the width direction of the unmanned transfer carriage A plurality of magnetic sensors are arranged side by side, and second magnetic sensors are arranged on both sides of the lower part of the unmanned transfer carriage in order to detect the magnetic tape constituting the magnetic marker.

Then, when the magnetic tape constituting the magnetic marker is sequentially detected by the second magnetic sensor, the unmanned transfer carriage moves according to the movement mode registered in advance in the detection order of the magnetic marker through the control device of the unmanned transfer carriage. The moving direction of the unmanned transfer carriage is controlled such that the magnetic tape constituting the guide path is always detected by a predetermined number of the plurality of first magnetic sensors. Here, in the control of the movement direction of the unmanned transfer carriage, the distance between the center position of the unmanned transfer carriage and the center position of the guideway (the magnetic tape constituting the guideway), that is, the truck offset is determined. By setting and decelerating the deceleration rate of one of the left and right drive wheels, correction of the movement direction (making the carriage displacement 0) is performed (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 10-111718

Since individual mechanical differences always exist in the left and right drive wheels that rotate the unmanned transfer carriage and the left and right drive mechanisms that respectively rotate the left and right drive wheels, for example, straight-ahead commands from the control device, that is, left and right drive Even if a command to rotate the wheels at the same speed is given, the unmanned transfer carriage generally does not go straight. Therefore, the operation response characteristic is grasped for each unmanned transfer carriage, and the movement procedure in consideration of the operation response characteristic is input to the command processing unit (for example, programmable logic controller) of the control device. Therefore, when correcting the movement procedure in response to a slight change in operation of the unmanned transfer carriage, the user's side of the unmanned conveyance carriage is careful work to correct the movement procedure while leaving the processing procedure regarding the operation response characteristic. At the same time, the manufacturer of the unmanned transfer carriage has a problem that control know-how such as processing procedures relating to operation response characteristics will be known.

In addition, since the state of the floor surface on which the unmanned transfer carriage moves varies depending on the location, and the movement characteristics of the unmanned transfer carriage are affected by the weight of the load, for example, the unmanned transfer carriage is not turned away from the taxiway , It is necessary to actually turn the unmanned transport carriage and finely adjust the turning radius at each turning point, and always make on-site adjustments (for example, gain adjustment in feedback control by PID) when laying or changing a guideway There is a problem that it has to be done.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an unmanned transfer carriage that can move along a guideway set on a floor surface without performing on-site adjustment.

An unmanned transport carriage according to the present invention in accordance with the above object comprises: a carriage capable of moving on a floor; and a carriage mounted on the carriage and moving the carriage along a guideway formed on the floor. An unmanned transport carriage comprising an automatic driving operation unit for inputting a command into the carriage unit,
The automatic driving operation unit comprises a carriage displacement detection means for sequentially obtaining and outputting a carriage displacement distance of the carriage portion being moved relative to the guide path;
A truck operation control unit configured to move the truck unit along the guide path while acquiring the truck shift distance and correcting the truck shift distance;
The carriage operation control unit outputs a rotational drive signal for controlling rotation of each of a plurality of driving wheels provided on the carriage when the carriage is moved and stopped;
A trajectory correction command unit which obtains rotation correction amounts of the plurality of drive wheels necessary for correcting the carriage displacement distance from the carriage displacement distance by sliding mode control, and outputs them as a rotation correction signal;
And a drive source control unit configured to input a rotation command signal formed by combining the rotation drive signal and the rotation correction signal to the rotation drive sources of the plurality of drive wheels.

In the unmanned transfer carriage according to the present invention, the switching line of the sliding mode control is determined by the carriage deviation angle between the guiding direction by the guide path and the movement direction of the carriage and the carriage deviation distance. be able to.
The truck shift distance and the truck shift angle are determined by the relationship between the unmanned transfer truck and the guideway, and are not affected by the uncertainty factor or the disturbance, so the site adjustment is not necessary.

In the unmanned transfer carriage according to the present invention, the drive wheels may be provided on the left and right sides in the width direction of the carriage portion, and the rotation correction signal may be a command to generate a rotational speed difference between the left and right drive wheels.
The unmanned transport carriage can be turned by turning the drive wheels of low rotational speed inside while keeping the moving velocity of the unmanned transport carriage by the command to generate the rotational speed difference between the left and right drive wheels.

In the unmanned transfer carriage according to the present invention, the guideway is made of magnetic tape, and the carriage deviation detection means is provided at the lower part of the carriage with a gap facing the floor surface along the width direction of the carriage. Between the magnetic tape center position in the width direction and the center position in the width direction of the carriage from an analog detection signal output when each magnetic sensor detects the magnetic tape It is preferable to have an operation unit for obtaining a distance, and an output unit for outputting the center-to-center distance as the truck offset distance.
Since the analog detection signal output from the magnetic sensor is used, it is possible to detect a change in the truck displacement with high accuracy and high speed.

In the unmanned transfer carriage according to the present invention, the operation unit is a signal processing circuit that digitizes the analog detection signal, and a digital signal processor (DSP) that obtains the center-to-center distance from the processing signal output from the signal processing circuit. And a shift distance calculation circuit having
The trajectory correction instruction unit further includes a digital signal processor for calculating the rotational speed difference between the left and right drive wheels by further obtaining the carriage displacement angle from the carriage displacement distance output from the carriage displacement detection means. Has an arithmetic circuit,
The carriage movement command unit has a programmable logic controller (PLC) that forms and outputs the rotational drive signals of the drive wheels on the left and right when moving the carriage along the guide path. preferable.

By providing the shift distance calculation circuit, calculation of the carriage shift distance can be performed at high speed, and by providing the rotation correction calculation circuit in the trajectory correction command unit, calculation of the rotational speed difference can be performed at high speed. Thereby, the sampling interval by the trajectory correction command unit can be shortened, and the limit cycle generated in the sliding mode control can be avoided.
In addition, by providing the programmable logic controller in the carriage movement command unit, the work of creating, changing and correcting the movement procedure of the unmanned transfer carriage becomes easy.
Furthermore, by processing the processing procedure related to the operation response characteristics of the unmanned transfer carriage necessary for calculation of the rotational speed difference into a chip and incorporating it in the rotation correction arithmetic circuit, processing speed can be increased and control know-how can be protected reliably. be able to.

In the unmanned transfer carriage according to the present invention, the carriage operation control means for moving the unmanned transfer carriage (cart) along the guideway while correcting the carriage deviation distance of the carriage of the unmanned transfer carriage with respect to the guideway performs sliding mode control. It is adopted. For this reason, for example, since the generated truck shift distance can be appropriately corrected without being affected by uncertain factors such as the state of the floor surface on which the unmanned transfer carriage moves and the weight change of the load, etc. There is no need for adjustment work at the site where the

In addition, a bogie movement control unit outputs a rotational drive signal for controlling each drive wheel of the bogie part, and a sliding mode control of rotation correction signals of each drive wheel necessary for correcting the generated bogie deviation distance. Since the truck movement command unit has a program for basic movement procedures (forward, reverse, turn, stop, acceleration, deceleration, etc.) of the unmanned transport carriage, trajectory correction The command unit can be loaded with a processing procedure relating to the operation response characteristics of the unmanned transfer carriage and a program for correcting the carriage displacement distance. As a result, the user of the unmanned transfer carriage can easily change the movement procedure for controlling the unmanned transfer carriage in the dolly movement command unit, and the manufacturer of the unmanned transfer carriage processes the operation response characteristics of the unmanned transfer carriage It becomes possible to easily protect control know-how such as procedures.

Since the bogie driving control means further includes a drive source control unit for inputting a rotation command signal obtained by combining the rotation drive signal and the rotation correction signal to the rotation drive source of each drive wheel, the rotation drive source of each drive wheel is simultaneously independent. It becomes easy to make it drive. In addition, when the rotation drive signal and the rotation correction signal are respectively converted to digital signals, the rotation command signals are also converted to digital signals, so that each rotation drive source can be controlled with high precision.

It is a top view of the unmanned carrier truck concerning one embodiment of the present invention. It is a side view of the unmanned conveyance truck. It is an explanatory view of a movement state of the unmanned conveyance truck. It is explanatory drawing which shows the structure of an automatic driving | operation operation part. It is an explanatory view showing the composition of a truck gap detection means.

Next, embodiments of the present invention will be described with reference to the attached drawings for understanding of the present invention.
As shown in FIGS. 1 and 2, the unmanned transfer carriage 10 according to the embodiment of the present invention is mounted on a carriage 12 which can move on the floor surface 11 and the carriage 12, and the carriage 12 is The automatic driving operation unit 14 inputs a movement command to be moved along the guiding path 13 made of a magnetic tape formed on the surface 11 to the carriage unit 12. In addition, from the magnetic tape, for example, the unmanned transfer carriage 10 (the carriage 12) is instructed to switch the moving state such as forward, reverse, turning, stopping, accelerating, and decelerating on both left and right sides of the guiding path 13. A plurality of magnetic markers (not shown) are arranged. The details will be described below.

As shown in FIG. 3, on the unmanned transfer carriage 10 moving on the floor surface 11, a two-dimensional direction in which the guiding direction by the guiding path 13 is the P axis direction and the direction orthogonal to the guiding direction of the guiding path 13 is the Q axis direction Set coordinate system. Therefore, when the movement of the carriage 12 is displaced relative to the guideway 13, the carriage displacement distance X is generated in the Q axis direction in the two-dimensional coordinate system, and the carriage displacement angle θ is the movement direction of the carriage 12 (the carriage 12 (The direction of the moving velocity V) of the lens and the P axis.

As shown in FIG. 1, FIG. 2 and FIG. 4, the automatic driving operation unit 14 sequentially detects and outputs a carriage displacement distance X with respect to the guiding path 13 of the carriage 12 under movement. A truck operation control means 16 is provided which acquires the shift distance X and moves the truck portion 12 along the guide path 13 while correcting the truck shift distance X.
Here, when the carriage operation control means 16 moves and stops the carriage 12, the left and right drive wheels 17, 18 provided on both sides in the width direction (left and right direction) of the carriage 12 can be used. Correction amounts of the drive wheels 17 and 18 required to correct the carriage displacement distance X from the carriage displacement distance X, and the carriage movement command unit 19 for outputting the rotational drive signal for controlling each rotation of A trajectory correction command unit 20 determined by sliding mode control and output as a rotation correction signal, and a rotation command signal formed by combining a rotation drive signal and a rotation correction signal are sent to rotation drive sources 21 and 22 of the drive wheels 17 and 18, respectively. And a drive source control unit 23 for inputting. Reference numerals 34 and 35 denote driven wheels provided on the left side in the width direction of the carriage 12, and reference numerals 36 and 37 denote driven wheels provided on the right side in the width direction of the carriage 12.

As shown in FIG. 5, the bogie misalignment detection means 15 has a plurality of Hall elements 24 (magnetic members arranged at intervals in the width direction of the bogie 12 facing the floor 11 at the lower part of the bogie 12). A guideway detection unit 25 provided with an example of a sensor and a width of the guideway 13 from an analog detection signal of each hall device 24 output from the guideway detection unit 25 when each hall element 24 detects the induction way 13 An arithmetic unit 26 for obtaining a center-to-center distance Δ between the direction center position and the width-direction center position of the carriage 12 and an output unit 27 for outputting the center distance Δ as the carriage displacement distance X.

The arithmetic unit 26 converts the analog detection signal output from each Hall element 24 into a signal processing circuit 28 (for example, an A / D converter) and a processing signal (digital signal) output from the signal processing circuit 28. And a shift distance calculation circuit 29 provided with a digital signal processor for determining the center distance Δ. Note that while the distance between the center of the Hall element 24 and the center in the width direction of the induction path 13 is changed in the displacement distance calculation circuit 29, the analog detection signal value output from the Hall element 24 is determined and created at that time. A database 30 composed of data on distance characteristics of the analog detection signal value of each Hall element 24 and the distance from the center in the width direction of the carriage 12 of each Hall element 24 is stored in advance. Therefore, in the shift distance calculation circuit 29, using the processing signal obtained by digitizing the analog detection signal output from each Hall element 24 and the data in the database 30, the center signal distance Δ can be made high accuracy and high speed by the digital signal processor. It can be calculated by As a result, it is possible to detect the fluctuation of the carriage displacement distance X caused by the carriage 12 which is moving, with high accuracy and high speed via the carriage displacement detection means 15.

As shown in FIG. 3, a bogie shift distance X is generated in the carriage 12 with respect to the guideway 13, and the guiding direction by the guideway 13 and the moving direction of the carriage 12 (direction of moving speed V of the carriage 12) Between the carriage displacement speed x of the carriage unit 12 (the time derivative of the carriage displacement distance X) and the movement velocity V of the carriage unit 12: x = V sin θ And when θ is small, it can be approximated as x = Vθ. Therefore, under the constraint that the moving speed V of the carriage 12 is constant, a sliding mode control system is configured with the angular velocity ω of the carriage offset angle θ as a control input.

The switching line of sliding mode control is given as X + αθ = 0 (α is a positive number affecting the movement of the carriage 12 under control) using the carriage displacement distance X and the carriage displacement angle θ. Here, in the sliding mode control, the displacement of the carriage 12 with respect to the guiding path 13 satisfies X + (α / V) x = 0 from x = Vθ, so the angular velocity ω, which is the control input, is Can be given in the form -kX. Here, k is a feedback gain, and the state (X, θ) of displacement of the carriage 12 with respect to the guiding path 13 in the change region determined by the carriage displacement distance X and the carriage displacement angle θ is the carriage displacement angle θ on the switching line. In this case, k is switched depending on whether it is on the + side, on the-side, on the + side with respect to the carriage displacement distance X on the switching line, or on the-side.

Assuming that the speeds of the left and right drive wheels 17 and 18 of the truck unit 12 are V _L and V _R and the distance between the left and right drive wheels 17 and 18 is S, the moving velocity V of the truck unit 12 is (V _L + V _R ) The angular velocity ω of the carriage offset angle θ is given by (V _L −V _R ) / S. For this reason, when the control input of the sliding mode control system is the angular velocity ω of the truck offset angle θ, the rotation correction signal output from the trajectory correction command unit 20 is a command that causes the left and right drive wheels 17 and 18 to generate a rotational speed difference. It becomes.
Under the constraint that the moving speed V of the carriage 12 is constant, when the rotational speed difference is generated in the left and right driving wheels 17 and 18, the moving speed V of the carriage 12 (the unmanned transfer carriage 10) is maintained. The low-rotational speed drive wheel is turned inward to cause the carriage 12 to turn, and the movement direction of the carriage 12 is corrected, whereby the carriage displacement distance X is reduced.

The trajectory correction command unit 20 further obtains a carriage displacement angle θ from the carriage displacement distance X output from the carriage displacement detection means 15, and the left and right drive wheels 17, 18 necessary for correcting the carriage displacement distance X and the carriage displacement angle θ. And a rotation correction operation circuit 31 provided with a digital signal processor that calculates the rotation speed difference. As a result, the calculation of the rotational speed difference can be performed at high speed, and the sampling interval by the trajectory correction command unit 20 of the carriage displacement distance X output from the carriage displacement detection means 15 can be shortened. As a result, it is possible to avoid the limit cycle generated in the sliding mode control.

The carriage movement command unit 19 has a programmable logic controller 32 that forms and outputs rotational drive signals of the left and right drive wheels 17 and 18 when moving the carriage 12 along the guide path 13. Here, since only the program of the moving procedure of the unmanned transfer carriage 10 is mounted on the programmable logic controller 32, the work of creating, changing and correcting the moving procedure of the unmanned transfer carriage 10 can be easily performed .

In the drive source control unit 23, for example, the rotational drive signal input from the programmable logic controller 32 to the rotational drive source 21 of the left drive wheel 17 and the side to be accelerated among the left and right drive wheels 17, 18 and trajectory correction The rotational command signal formed by adding the rotational speed difference (rotation correction signal) input from the command unit 20 is input, and the side decelerated among the left and right drive wheels 17 and 18, for example, the right drive wheel A rotational speed adjustment circuit 33 is provided to input a rotational command signal formed by subtracting the rotational speed difference from the rotational drive signal to the 18 rotational drive sources 22.

Subsequently, the operation of the unmanned transfer carriage 10 according to the embodiment of the present invention will be described.
In the unmanned transfer carriage 10, the carriage operation control means 16 for moving the carriage 12 (the unmanned transfer carriage 10) along the guide route 13 while correcting the carriage displacement distance X of the carriage 12 with respect to the guide route 13 Is adopted. Therefore, for example, the generated truck displacement distance X can be appropriately corrected without being affected by uncertain factors such as the state of the floor surface 11 on which the unmanned transport carriage 10 moves and the weight change of the load, etc. Adjustment work at the site where the unmanned transfer carriage 10 moves becomes unnecessary.

Further, the carriage movement control unit 19 outputs the rotational drive signal for controlling the left and right drive wheels 17 and 18 of the carriage 12 and the left and right drive necessary for correction of the generated carriage displacement distance X. Since the trajectory correction command unit 20 for obtaining and outputting rotation correction signals of the wheels 17 and 18 by sliding mode control, the carriage movement command unit 19 performs basic movement procedures of the unmanned transfer carriage 10 (forward, reverse, turn, A program for stopping, accelerating, decelerating, etc.) can be installed in the trajectory correction command unit 20, respectively.

As a result, the user of the unmanned transfer carriage 10 can easily change the movement procedure for controlling the unmanned transfer carriage 10 by changing the program mounted on the carriage movement command unit 19. On the other hand, the manufacturer of the unmanned transfer carriage 10 can, for example, chip and integrate a program for control know-how such as a processing procedure related to the operation response characteristic of the unmanned transfer carriage 10 into the rotation correction arithmetic circuit 31. Protection can be ensured.

Since the carriage operation control means 16 has the drive source control unit 23 which inputs the rotation command signal combining the rotation drive signal and the rotation correction signal to the rotation drive sources 21 and 22 of the left and right drive wheels 17 and 18, It becomes possible to simultaneously drive the rotary drive sources 21 and 22 of the wheels 17 and 18 independently. Further, when the rotation drive signal and the rotation correction signal are respectively converted to digital signals, the rotation command signals are also converted to digital signals, so that the rotation drive sources 21 and 22 can be controlled with high accuracy.

Although the present invention has been described above with reference to the embodiment, the present invention is not limited to the configuration described in the above-described embodiment, and the items described in the appended claims It also includes other embodiments and modifications that are considered within the scope.
Furthermore, combinations of components included in the present embodiment and other embodiments and modifications are also included in the present invention.

10: Unmanned conveyance carriage, 11: floor, 12: carriage, 13: taxiway, 14: automatic operation operation unit, 15: carriage deviation detection means, 16: carriage operation control means, 17: left drive wheel, 18 : Right driving wheel, 19: Carriage movement command unit, 20: Trajectory correction command unit, 21, 22: Rotational drive source, 23: Drive source control unit, 24: Hall element, 25: Induction path detector, 26: Calculation Part 27: Output part 28: Signal processing circuit 29: Deviation distance arithmetic circuit 30: Database 31: Rotation correction arithmetic circuit 32: Programmable logic controller 33: Rotational speed adjustment circuit 34, 35, 36 37: driven wheel

Claims (5)

A carriage unit movable on a floor surface, and an automatic operation operation unit mounted on the carriage unit and inputting to the carriage unit a movement command for moving the carriage unit along a guideway formed on the floor surface; In an unmanned transport carriage equipped with
The automatic driving operation unit comprises a carriage displacement detection means for sequentially obtaining and outputting a carriage displacement distance of the carriage portion being moved relative to the guide path;
A truck operation control unit configured to move the truck unit along the guide path while acquiring the truck shift distance and correcting the truck shift distance;
The carriage operation control unit outputs a rotational drive signal for controlling rotation of each of a plurality of driving wheels provided on the carriage when the carriage is moved and stopped;
A trajectory correction command unit which obtains rotation correction amounts of the plurality of drive wheels necessary for correcting the carriage displacement distance from the carriage displacement distance by sliding mode control, and outputs them as a rotation correction signal;
And a drive source control unit configured to input a rotation command signal formed by combining the rotation drive signal and the rotation correction signal to the rotation drive sources of the plurality of drive wheels. The unmanned transfer carriage according to claim 1, wherein the switching line of the sliding mode control is determined by a bogie deviation angle between the guiding direction by the guiding path and the movement direction of the bogie part and the bogie deviation distance. An unmanned transport truck featuring. The unmanned transfer carriage according to claim 2, wherein the drive wheels are provided on both left and right sides in the width direction of the carriage portion, and the rotation correction signal is a command to generate a rotational speed difference between the left and right drive wheels. An unmanned transport carriage. 4. The unmanned transfer carriage according to claim 3, wherein the guide path is made of magnetic tape, and the carriage displacement detection means is disposed at a lower portion of the carriage facing the floor surface and a gap along the width direction of the carriage. A plurality of magnetic sensors provided and arranged, and a central position in the width direction of the magnetic tape and a central position in the width direction of the carriage from an analog detection signal output when each magnetic sensor detects the magnetic tape An unmanned carrier according to claim 1, further comprising: an operation unit for obtaining an inter-distance, and an output unit for outputting the center-to-center distance as the truck offset distance. 5. The unmanned transfer carriage according to claim 4, wherein the operation unit includes a signal processing circuit that digitizes the analog detection signal, and a digital signal processor that obtains the center-to-center distance from a processing signal output from the signal processing circuit. And a distance shift calculation circuit,
The trajectory correction instruction unit further includes a digital signal processor for calculating the rotational speed difference between the left and right drive wheels by further obtaining the carriage displacement angle from the carriage displacement distance output from the carriage displacement detection means. Has an arithmetic circuit,
The carriage movement command unit has a programmable logic controller that forms and outputs the rotational drive signals of the drive wheels on the left and right when moving the carriage along the guide path. Unmanned transport carriage.

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