JP2022119114A - Industrial vehicle, method for controlling industrial vehicle and program - Google Patents

Abstract

To provide an industrial vehicle capable of acquiring appropriate traveling performance by maintaining the accuracy of traveling control, a method for controlling an industrial vehicle and a program.SOLUTION: An industrial vehicle (an unmanned forklift) 10 includes a traveling body 10A, a laser sensor 10C1 installed in the traveling body through a lifting device 10D to transmit a laser beam to a plurality of reflection plates installed in a traveling environment and receive reflection light, an arithmetic unit 11 for calculating the position and the direction of the traveling body on the basis of an output of the laser sensor, and a control device 13 for controlling traveling of the traveling body on the basis of calculation results of the position and the direction. The control device controls traveling of the traveling body with acceleration at which prescribed request accuracy calculated by using a model representing a relation among accuracy in control over the traveling of the traveling body, acceleration of the traveling body and the height of the laser sensor can be obtained, as an upper limit.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to industrial vehicles, industrial vehicle control methods, and programs.

Patent Literature 1 discloses a laser automatic guided vehicle configured so that the transmitted and received laser beams are not blocked by baggage or the like. The unmanned forklift, which is a laser-type unmanned guided vehicle described in Patent Document 1, transmits a laser beam while horizontally rotating 360 degrees, and receives the laser beam reflected by a reflector installed in the warehouse. A laser scanner and an unmanned vehicle that travels based on the recognition result of the reflector by the laser scanner are provided. In this unmanned forklift, the laser scanner is provided to be able to move up and down so that the height of the laser scanner can be changed.

Japanese Patent Application Laid-Open No. 2020-30642

In the unmanned forklift described in Patent Document 1, when the laser scanner is moved to a high position by the lifting device, the laser scanner and the reflector plate are affected by the inclination of the floor surface on which the traveling body travels and the vibration of the traveling body during travel. Since the distance to and from the vehicle may fluctuate, there was a problem that it was necessary to set the acceleration and travel speed during acceleration and deceleration to values with sufficient leeway so that the accuracy of travel control could be maintained. .

The present disclosure has been made to solve the above problems, and aims to provide an industrial vehicle, an industrial vehicle control method, and a program that can maintain the accuracy of travel control and obtain appropriate travel performance. aim.

In order to solve the above problems, an industrial vehicle according to the present disclosure transmits a laser beam to a traveling body and a plurality of reflectors installed on the traveling body via an elevating device and installed in a traveling environment. a laser sensor for receiving reflected light, an arithmetic device for calculating the position and orientation of the traveling object based on the output of the laser sensor, and a control device for controlling the traveling of the traveling object based on the results of the calculation of the position and orientation. wherein the control device has a predetermined required accuracy obtained using a model representing the relationship between at least the accuracy in controlling the traveling of the traveling body, the acceleration of the traveling body, and the height of the laser sensor. The traveling of the traveling body is controlled with the obtained acceleration as an upper limit.

A control method for an industrial vehicle according to the present disclosure transmits a laser beam to a traveling body and a plurality of reflectors installed on the traveling body via an elevating device and installed in a traveling environment, and receives the reflected light. and a laser sensor for controlling an industrial vehicle, the method comprising: calculating the position and orientation of the traveling object based on the output of the laser sensor; When controlling the traveling, a predetermined required accuracy obtained by using at least a model representing the relationship between the accuracy in the control of the traveling of the traveling body, the acceleration of the traveling body, and the height of the laser sensor can be obtained. and controlling the running of the running body with the acceleration as an upper limit.

A program according to the present disclosure includes a traveling body, a laser sensor that is installed on the traveling body via an elevating device, transmits a laser beam to a plurality of reflectors installed in a traveling environment, and receives the reflected light. and calculating the position and orientation of the traveling object based on the output of the laser sensor; , at least the acceleration at which a predetermined required accuracy obtained using a model representing the relationship between the accuracy in the control of the running of the running body, the acceleration of the running body, and the height of the laser sensor is obtained, and a step of controlling the running of the running body.

According to the industrial vehicle, industrial vehicle control method, and program of the present disclosure, it is possible to maintain the accuracy of the travel control and obtain appropriate travel performance.

1 is a block diagram showing a configuration example of an unmanned forklift as an example of an industrial vehicle according to an embodiment of the present disclosure; FIG. FIG. 2 is a side view schematically showing a configuration example of the unmanned forklift 10 shown in FIG. 1; 1 is a perspective view schematically showing an outline of an unmanned guided vehicle system according to an embodiment of the present disclosure; FIG. 1 is a side view schematically showing an outline of an unmanned guided vehicle system according to an embodiment of the present disclosure; FIG. FIG. 2 is a schematic diagram for explaining an operation example of the unmanned forklift 10 shown in FIG. 1; 2 is a system diagram showing a configuration example of an acceleration calculator 31 and a control device 13 shown in FIG. 1; FIG. 7 is a schematic diagram showing a configuration example of a processing database 331 shown in FIG. 6; FIG. 7 is a schematic diagram showing a configuration example of a processing database 341 shown in FIG. 6; FIG. FIG. 7 is a schematic diagram showing a configuration example of an acceleration upper limit table 14 shown in FIGS. 1 and 6; FIG. Fig. 10 is a side view schematically showing a configuration example of an unmanned forklift 10a according to a second embodiment of the present disclosure; FIG. 11 is a partial front view schematically showing the unmanned forklift 10a shown in FIG. 10; FIG. 11 is a side view schematically showing a configuration example of unmanned forklifts 10b-1 to 10b-3 according to a third embodiment of the present disclosure; 1 is a schematic block diagram showing a configuration of a computer according to at least one embodiment; FIG.

<First Embodiment>
(Basic Configuration and Operation of Unmanned Forklift 10)
A configuration and operation example of an unmanned forklift according to a first embodiment of the present disclosure will be described below with reference to FIGS. 1 to 4. FIG. In each figure, the same reference numerals are used for the same or corresponding configurations, and the description thereof will be omitted as appropriate. FIG. 1 is a block diagram showing a configuration example of an unmanned forklift 10 as an example of an industrial vehicle according to an embodiment of the present disclosure. FIG. 2 is a side view schematically showing a configuration example of the unmanned forklift 10 shown in FIG. 1. As shown in FIG. FIG. 3 is a perspective view schematically showing the outline of the unmanned guided vehicle system 1 according to the embodiment of the present disclosure. FIG. 4 is a side view schematically showing the outline of the unmanned guided vehicle system 1 according to the embodiment of the present disclosure. In addition, the industrial vehicle according to the embodiment of the present disclosure is not limited to an unmanned forklift, and may be general laser-guided unmanned vehicles.

As shown in FIGS. 1 to 4, an unmanned forklift 10 according to the first embodiment of the present disclosure includes an unmanned traveling body (hereinafter referred to as traveling body) 10A, a cargo handling device 10B, a laser scanner 10C, and a lifting device 10D. Prepare. As shown in FIG. 3, the traveling object 10A estimates its own position based on the recognition results of a plurality of reflectors 50 installed in the traveling environment such as the warehouse 40, and automatically moves on the floor surface 43 inside the warehouse 40. run. As shown in FIG. 3, the automatic guided vehicle system 1 according to the present embodiment includes an unmanned forklift 10 that is a laser automatic guided vehicle, a plurality of reflectors 50 provided in a warehouse 40, and a plurality of reflectors 50 for storing packages N. a shelf 70 and a floor placing area for luggage N.

The reflector 50 is fixed to a general wall 41 or fire wall 42 in the warehouse 40 and arranged at a predetermined height so as to reflect the laser beam LA from the unmanned forklift 10 . From the viewpoint of improving the estimation accuracy of the current position of the unmanned forklift 10, it is preferable that a large number of reflectors 50 are provided.

The laser scanner 10C is installed on the traveling body 10A via the lifting device 10D, transmits a laser beam LA to a plurality of reflectors 50 installed in the traveling environment (inside the warehouse 40), and receives the reflected light. It has a sensor 10C1 (see FIG. 1). The laser scanner 10C is provided so as to be able to move up and down with respect to the traveling body 10A by means of a lifting device 10D. Laser light LA (reflected light) that is transmitted and reflected by the reflector 50 is received. The laser scanner 10C outputs the time from transmission to reception of the laser beam LA and the movement direction angle of the laser beam LA reflected by the reflector 50 as the reception result of the laser beam LA. Note that the laser scanner 10C according to the present embodiment is attached to the traveling body 10A via the lifting device 10D, but may be attached to the cargo handling device 10B.

As shown in FIGS. 1 and 2, the unmanned forklift 10 includes a computing device 11, a traveling device 12, and a control device 13 as components of a traveling body 10A. Based on the reception result of the laser beam LA received by the laser scanner 10C, the arithmetic device 11 recognizes three or more reflectors 50 that have reflected the laser beam LA, and calculates the distance from the laser scanner 10C to the reflector 50 and the reflection. The angle (orientation) of the plate 50 is calculated. Specifically, the arithmetic device 11 calculates the distance from the laser scanner 10C to the reflector 50 based on the time from when the laser beam LA is transmitted until it is received, and calculates the distance from the laser beam reflected by the reflector 50. The angle of the reflector 50 is calculated based on the movement direction angle of LA. Then, the calculation device 11 estimates the current position and orientation of the unmanned forklift 10 based on the calculation result of the distance and angle to the reflector 50 . That is, the computing device 11 computes the current position (Xc, Yc) and orientation (θc) of the traveling body 10A based on the outputs of the laser sensor 10C1 for the three or more reflectors 50. FIG. Here, (Xc, Yc) are coordinate values in a two-dimensional coordinate system defined in the warehouse 40, for example, and θc is an angle with respect to a reference direction.

The travel device 12 has a driving device and a steering device (not shown) therein, and travels in the warehouse 40 to carry out loading and unloading operations. The control device 13 controls the traveling device 12 so that the traveling body 10</b>A travels a preset route in the warehouse 40 based on the estimation result of the current position of the unmanned forklift 10 . That is, the control device 13 controls the running of the running body 10A based on the calculation result of the position and orientation of the running body 10A by the arithmetic device 11 . The control device 13 includes an acceleration upper limit table 14, and controls the traveling of the traveling body 10A with the acceleration set in the acceleration upper limit table 14 as the upper limit. In addition, the control device 13 controls a lift device 22, which will be described later, so that the cargo handling device 10B performs loading and unloading operations.

The unmanned forklift 10 includes a fork 21 and a lift device 22 as components of the cargo handling device 10B. The fork 21 is provided so as to be able to move up and down, and supports the load N. The lift device 22 includes a vertically extending mast 22A (see FIG. 2) and a lift bracket 22B (see FIG. 2) that moves along the mast 22A. A fork 21 is attached to the lift bracket 22B, and the lift device 22 raises and lowers the fork 21 by vertically moving the lift bracket 22B. The cargo handling apparatus 10B performs cargo placement work of placing the cargo N on the shelf 70 or the floor placement area of the cargo N, and picking up of the cargo N from the shelf 70 or the floor placement area of the cargo N.

The unmanned forklift 10 also includes a lifting device 10D that supports the laser scanner 10C. The lifting device 10D has, for example, a structure called a telescopic (registered trademark) pick that expands and contracts a plurality of overlapping cylinders, and lifts and lowers the laser scanner 10C (laser sensor 10C1) in the vertical direction. In the example shown in cylinder FIG. 2, the lifting device 10D has three cylinders 10D1, 10D2 and 10D3 which are superimposed and can be lifted vertically, e.g. , the laser scanner 10C is moved up and down. The lifting device 10</b>D is controlled by the control device 13 . The lifting and lowering of the laser scanner 10C by the lifting device 10D is independent of the lifting and lowering of the fork 21. FIG. Also, the tubes 10D1, 10D2, and 10D3 can be cylinders, square tubes, polygonal tubes, or the like.

In this embodiment, as shown in FIG. 2, the laser scanner 10C is provided to be able to move up and down. A state where the laser scanner 10C is provided, a state where the laser scanner 10C is provided at the lowest position as shown as an unmanned forklift 10-2 in FIG. For example, as shown in FIG. 4, the unmanned forklift 10 moves under the fire wall 42 by retracting the lifting device 10D so that the laser scanner 10C is provided at the lowest position. After passing through, the lifting device 10D is extended to set the laser scanner 10C at the highest position or the middle position.

(Configuration and Operation of Acceleration Calculation Device 30)
Next, the configuration and operation of the acceleration calculation device 30 shown in FIG. 1 will be described with reference to FIGS. 5 to 9. FIG. The acceleration calculation device 30 is implemented as a computing device such as a computer provided outside the unmanned forklift 10, for example. Note that the acceleration calculation device 30 may be included in the unmanned forklift 10 . FIG. 5 is a schematic diagram for explaining an operation example of the unmanned forklift 10 shown in FIG. FIG. 6 is a system diagram showing a configuration example of the acceleration calculator 31 and the control device 13 shown in FIG. FIG. 7 is a schematic diagram showing a configuration example of the processing database 331 shown in FIG. FIG. 8 is a schematic diagram showing a configuration example of the processing database 341 shown in FIG. FIG. 9 is a schematic diagram showing a configuration example of the acceleration upper limit table 14 shown in FIGS. 1 and 6. As shown in FIG.

The acceleration calculation device 30 calculates acceleration (deceleration during deceleration (negative acceleration) and Calculate the upper limit of acceleration (positive acceleration). The acceleration calculator 30 shown in FIG. 1 includes an acceleration calculator 31 . The acceleration calculator 31 includes a storage unit 32 . The storage unit 32 stores the first model 33 , the second model 34 and the experimental data 35 . The experimental data 35 includes a plurality of measurement results of stop positioning errors and travel locus errors obtained in actual travel control of the unmanned forklift 10 . The experimental data 35 is, for example, the stop positioning error when the height of the laser sensor 10C1, the traveling speed of the traveling body 10A, the inclination of the floor surface on which the traveling body 10A travels, and the shake of the laser sensor 10C1 accompanying traveling are changed. and multiple measurement results for trajectory error.

The first model 33 is a reference model for control to ensure "stopping positioning accuracy" when the vehicle is stopped. The first model 33 is a model used when calculating the upper limit value of the acceleration at which a predetermined required accuracy is obtained for the stop positioning accuracy. It can be a combination of a program that performs calculation from input (required accuracy) to output (upper limit of acceleration) based on 35 and data used for the calculation. In the present embodiment, the reference model refers to, for example, the characteristics and performance of a product or a similar product based on experimental data and simulation results obtained in the design stage, prototype stage, initial production stage, etc. It means a formula, a program, a combination of a program and data, etc. for calculating a numerical value that can be referred to as a reference value or a predicted value.

The second model 34 is a reference model for control to ensure "running locus accuracy" when the vehicle is running. The second model 34 is a model used when calculating the upper limit value of the acceleration at which a predetermined required accuracy is obtained for the accuracy of the traveling locus. It can be a combination of a program that performs calculation from input (required accuracy) to output (upper limit of acceleration) based on 35 and data used for the calculation.

In this embodiment, the stop positioning accuracy means the width of variation when the error between the target stop position and the actual stop position is repeatedly measured a plurality of times. For the stop positioning accuracy, for example, as shown in FIG. 3, when the traveling body 10A is automatically run from the current position P0 to the position Pr as the target stop position, the distance between the actually stopped position P1 and the position Pr is measured a plurality of times. It can be the standard deviation that is sometimes obtained. Further, in the present embodiment, the running locus accuracy means the width of variation when the error between the target locus and the actual locus is measured multiple times. For example, as shown in FIG. 3, the target trajectory is the target trajectory Tr, and the traveling body 10A is automatically caused to travel from the current position P0 to the target stop position Pr. and the standard deviation obtained when the distance of the target trajectory Tr is measured multiple times.

Further, as shown in FIG. 5, in the case of a laser-guided unmanned forklift, the inclination θ1 of the floor surface and the traveling height H (sensor height H) of the laser scanner 10C (laser sensor 10C1) by the elevating mechanism correspond to the height H of the laser scanner 10C (laser sensor 10C1). Since the distance L between the reflector 50 and the laser scanner 10C changes due to the tilt θ2 due to the vehicle vibration at the time, a difference ΔL occurs in the self-positioning of the unmanned forklift 10 . Here, the difference ΔL is the difference between the distance between the laser scanner 10C-1 and the reflector 50 when the inclination is small and the distance between the laser scanner 10C-2 and the reflector 50 when the inclination is large. It can be approximated by H×tan θ. Here, H is the height of the laser scanner 10C (laser sensor 10C1) from the floor, θ is the sum of the inclination θ1 of the floor surface and the inclination θ2 due to vehicle vibration during running, and the vertical direction of the laser sensor 10C1. This is the difference in inclination between the laser scanner 10C-1 when the inclination is small and the laser scanner 10C-2 when the inclination is large. For example, when the height H is 5 m and 2 m, the difference ΔL is 2.5 times larger when the height H is 5 m, and when the inclination θ is 1 deg and 2 deg, the difference ΔL is twice as large when the inclination is 2 deg.

In the configuration example shown in FIG. 6 , the first model 33 includes a processing database 331 and a gain Kstop calculator 332 . The gain Kstop calculation unit 332 receives the required stop positioning accuracy σ_req_stop and outputs the required stop positioning accuracy σ_req_stop multiplied by the gain Kstop. The processing database 331 is composed of, for example, data used for processing and a program for processing the data, and inputs the required stop positioning accuracy σ_req_stop multiplied by the gain Kstop, the sensor height H, and the running speed V of the running body 10A. , to output the deceleration α_stop for stopping. The stop deceleration α_stop is the upper limit value of the stop deceleration αd that can achieve the required stop positioning accuracy σ_req_stop.

A gain Kstop calculation unit 332 multiplies the required stop positioning accuracy σ_req_stop by a gain Kstop (Kstop>1) and outputs the required stop positioning accuracy σ_req_stop multiplied by the gain Kstop. Unquantified amount that cannot be quantified or determined depending on the environment (effect of floor surface inclination θ1, effect of sensor shake θ2 accompanying running, or inclination of laser sensor 10C1 that integrates influence of floor surface inclination θ1 and sensor shake θ2 accompanying running θ = θ1 + θ2) is provided with a “gain Kstop”, and the value of the required stop accuracy σ_req_stop is finely adjusted (corrected) to make the required accuracy stricter. The impact of the inability to quantify However, depending on the degree of their influence, the gain Kstop calculator 332 may be omitted. In this case, the requested stop positioning accuracy σ_req_stop input to the first model 33 is input to the processing database 331 as it is.

The processing database 331 can be composed of two models 331a and 331b and a minimum value selector 331c, as shown in FIG. 7, for example. The model 331a includes a standard deviation σ_stop representing the stop positioning accuracy of the running body 10A, a deceleration αd for stopping the running body 10A, and sensor heights H (H1, H2, H3, . . . (however, H1>H2>H3> . )). The model 331a inputs the required stop positioning accuracy σ_req_stop and the sensor height H, and outputs the stop deceleration αstop_a that realizes the required stop positioning accuracy. In the example shown in FIG. 7, for example, when the sensor height H is "H2", the model 331a calculates the stop deceleration corresponding to the intersection point CPa between the horizontal line corresponding to the required stop positioning accuracy σ_req_stop and the curve of the sensor height H2. αd is output as the stop deceleration αstop_a that achieves the required stop positioning accuracy. On the other hand, the model 331b includes a standard deviation σ_stop representing the stop positioning accuracy of the running body 10A, a deceleration αd at which the running body 10A stops, and a running speed V (V1, V2, V3, . . . (where V1> V2>V3>...))). The model 331b inputs the required stop positioning accuracy σ_req_stop and the running speed V, and outputs the stop deceleration αstop_b that realizes the required stop positioning accuracy. In the example shown in FIG. 7, for example, when the travel speed V is "V1", the model 331b determines the stop deceleration αd corresponding to the intersection point CPb between the horizontal line corresponding to the required stop positioning accuracy σ_req_stop and the curve of the travel speed V1. , as the stop deceleration αstop_b that realizes the required stop positioning accuracy. Then, the minimum value selection unit 331c inputs the deceleration αstop_a and the deceleration αstop_b, and outputs the smaller value (the one with the smaller absolute value) as the stop deceleration α_stop (=MIN(αstop_a, αstop_b).

In addition, in the configuration example shown in FIG. 6, the second model 34 includes a processing database 341 and a gain Kstart calculator 342 . The Kstart calculation unit 342 receives the required travel locus accuracy σ_req_start and outputs the required travel locus accuracy σ_req_start multiplied by the gain Kstart. The processing database 341 is composed of, for example, data used for processing and a program for processing the data. , to output the running acceleration α_start. The running acceleration α_start is the upper limit value of the running acceleration αa that can achieve the required running locus accuracy σ_req_start.

A gain Kstart calculation unit 342 multiplies the required travel locus accuracy σ_req_start by a gain Kstart (Kstart>1) and outputs the required travel locus accuracy σ_req_start multiplied by the gain Kstart. Unquantifiable amount that cannot be quantified or determined depending on the environment (the influence of the floor surface inclination θ1, the effect of the sensor shake θ2 accompanying running, or the inclination of the laser sensor 10C1 that integrates the influence of the floor surface inclination θ1 and the sensor shake θ2 accompanying running θ = θ1 + θ2) is provided with “gain Kstart”, the value of the required running locus accuracy σ_req_start is finely adjusted (corrected), and the required accuracy is made stricter, so that the floor inclination θ1 and the sensor shake accompanying running This suppresses the influence of not being able to quantify θ2. However, the gain Kstart calculator 342 may be omitted depending on the degree of their influence. In this case, the required travel locus accuracy σ_req_start input to the second model 34 is input to the processing database 341 as it is.

The processing database 341 can be composed of two models 341a and 341b and a minimum value selector 341c, as shown in FIG. 8, for example. The model 341a includes a standard deviation σ_start representing the running locus accuracy of the running body 10A, a running acceleration αa of the running body 10A, and sensor heights H (H1, H2, H3, . This model represents the relationship between The model 341a inputs the required running locus accuracy σ_req_start and the sensor height H, and outputs the running acceleration αstart_a that realizes the required running locus accuracy. In the example shown in FIG. 8, when the sensor height H is "H2", the model 341a calculates the running acceleration αa corresponding to the intersection CPa between the horizontal line corresponding to the required running locus accuracy σ_req_start and the curve of the sensor height H2. , as the running acceleration αstart_a that realizes the required running locus accuracy. On the other hand, the model 341b has a standard deviation σ_start representing the running locus accuracy of the running body 10A, a running acceleration αa of the running body 10A, and a running speed V (V1, V2, V3, . . . (where V1>V2> V3>...))). The model 341b inputs the required running locus accuracy σ_req_start and the running speed V, and outputs the running acceleration αstart_b that realizes the required running locus accuracy. In the example shown in FIG. 8, for example, when the running speed V is "V1", the model 341b requests the running acceleration αa corresponding to the intersection point CPb between the horizontal line corresponding to the required running locus accuracy σ_req_start and the curve of the running speed V1. It is output as the running acceleration αstart_b that realizes the running locus accuracy. Then, the minimum value selection unit 341c inputs the running acceleration αstart_a and the reduced running acceleration αstart_b, and outputs the smaller value as the running acceleration α_start (=MIN(αstart_a, αstart_b).

The acceleration upper limit values (deceleration α_stop and running acceleration α_start) calculated by the acceleration calculator 31 shown in FIG. FIG. 9 shows an example of the acceleration upper limit value table 14 set based on the upper limit value of acceleration calculated by the acceleration calculator 31 . In the example shown in FIG. 9, the acceleration upper limit table 14 includes a table 14-1 and a table 14-2. Table 14-1 shows the stop deceleration α_stop (“○○ (indicated by ◯)). Table 14-2 shows the acceleration α_start (“○○○ )). Note that the acceleration upper limit value table 14 is not limited to the example shown in FIG. It is possible to divide into a plurality of ranges and set the acceleration upper limit value for each divided range.

Note that the first model 33 and the second model 34 are not limited to models based on the results of regression analysis, and may be models based on machine learning, for example. Further, the first model 33 can also be used as a model representing the relationship between the standard deviation σ_stop, which represents the stop positioning accuracy, and the sensor height H, for example, in an environment where the influence of the traveling speed V is relatively small (negligible). good. Further, the first model 33 may be a model that expresses the relationship between the floor inclination θ1, the sensor shake θ2 due to running, the inclination θ=θ1+θ2 of the laser sensor 10C1, and the like. In addition, the second model 34 can also be used as a model that expresses the relationship between the standard deviation σ_start that represents the travel locus accuracy and the sensor height H, for example, in an environment where the influence of the travel speed V is relatively small (can be ignored). good. Further, the second model 34 may be a model representing the relationship between the floor inclination θ1, the sensor shake θ2 due to running, the inclination θ=θ1+θ2 of the laser sensor 10C1, and the like. Either one of the first model 33 and the second model 34 may be omitted.

(Configuration and operation of control device 13)
A configuration and operation example of the control device 13 will be described with reference to FIG. A control device 13 shown in FIG. The driving pattern calculation unit 15 inputs the vehicle speed command Vr, the vehicle target position (Xr, Yr, θr), and the vehicle current position (Xc, Yc, θc), and calculates the acceleration upper limit value table 14 and the deceleration/acceleration pattern. to calculate the driving pattern. Here, the deceleration/acceleration pattern can be not only a trapezoid but also a secondary or tertiary S-shape, a sine wave, or the like. Further, the vehicle target position (Xr, Yr, θr) is a coordinate value and angle command value in the same coordinate system as the current vehicle position (Xc, Yc, θc). The trajectory to is represented as a series of points. The driving pattern calculation unit 15 calculates a deceleration start point, an acceleration end point, a constant speed driving section, etc. as information representing the driving pattern, and outputs the information to the vehicle driving control unit 16 . At that time, the traveling pattern calculation unit 15 calculates the traveling pattern so that the upper limit of the acceleration or deceleration is not exceeded based on the height H of the lifting device 10D determined for each predetermined area. The vehicle driving control unit 16 inputs the driving pattern calculated by the driving pattern calculation unit 15 and the current vehicle position (Xc, Yc, θc), and controls the traveling device 12 based on the instructed driving pattern.

(Action and effect of the first embodiment)
A model based on experimental data is used to calculate the upper limit of acceleration that can ensure accurate performance, so it is possible to maintain the accuracy of travel control and obtain appropriate travel performance.

(Aspect of the first embodiment)
1st Embodiment mentioned above can be grasped as the following aspect. That is, one aspect of the first embodiment is to irradiate a laser beam to a plurality of reflectors 50 installed on the traveling body 10A via the traveling body 10A and the lifting device 10D and installed in the traveling environment, and to reflect the laser light. and a laser sensor 10C1 for receiving light, and a method for controlling an unmanned forklift 10 as an example of an industrial vehicle, the step of calculating the position and orientation of the traveling body 10A based on the output of the laser sensor 10C1 with respect to the reflector 50. and a model representing at least the accuracy in controlling the running of the running body 10A and the relationship between the acceleration of the running body 10A and the height of the laser sensor 10C1 when controlling the running of the running body 10A based on the calculation results of the position and orientation. and controlling the traveling of the traveling body 10A with the upper limit of the acceleration at which the predetermined required accuracy obtained by using is controlled.

Further, the control device 13 and the arithmetic device 11 can be configured by a combination of a computer and a program executed by the computer. and a laser sensor 10C1 that is installed on the traveling body 10A and that irradiates laser light onto a plurality of reflectors 50 that are installed in the traveling environment and receives the reflected light. a step of calculating the position and orientation of the traveling object based on the output of the laser sensor 10C1 for the laser sensor 10C1; and a step of controlling the traveling of the traveling body 10A with the upper limit of the acceleration at which a predetermined required accuracy obtained using a model representing the relationship between the acceleration of the traveling body and the height of the laser sensor 10C1 is executed. It can be taken as a program.

<Second embodiment>
Next, a configuration example of an unmanned forklift 10a according to a second embodiment of the present disclosure will be described with reference to FIGS. 10 and 11. FIG. FIG. 10 is a side view schematically showing a configuration example of an unmanned forklift 10a according to the second embodiment of the present disclosure. FIG. 11 is a partial front view schematically showing the unmanned forklift 10a shown in FIG.

As shown in FIG. 10, unlike the unmanned forklift 10 (FIG. 2) according to the first embodiment, the unmanned forklift 10a according to the second embodiment has a lifting device 10D installed on a bracket 22C fixed to a mast 22A. ing. 10 and 11, one end 61 of turnbuckle 60 is detachably fixed to mast 22A via bracket 22D, and the other end 62 of turnbuckle 60 connects bracket 10A-2. It is detachably fixed to the running body 10A via the . The bracket 22D is fixed to the mast 22A and has a screw hole 22E for a screw 81 for fastening the end portion 61 to the bracket 22D. Also, the bracket 10A-2 is fixed to the vehicle body 10A-1 of the traveling body 10A, and has a screw hole 10A-3 for a screw 82 for fixing the end portion 62 to the bracket 10A-2 with a screw 82. there is In this configuration, bracket 22D and bracket 10A-2 serve as mounting interfaces for each end of turnbuckle 60. A turnbuckle 60 (not shown) is also attached to the unmanned forklift 10a on the opposite side of FIG. 10 in the depth direction.

In the second embodiment, by using one set of turnbuckles 60, vibration of the mast 22A can be suppressed as compared with the case where no turnbuckles are used. Therefore, the influence of the inclination θ2 due to vehicle vibration can be suppressed.

<Third Embodiment>
Next, a configuration example of an unmanned forklift 10a according to a third embodiment of the present disclosure will be described with reference to FIG. FIG. 12 is a side view schematically showing a configuration example of unmanned forklifts 10b-1 to 10b-3 according to the third embodiment of the present disclosure. The forklift 10b-1 is in a state where the cylinders 10D1 and 10D2 are extended by the lifting device 10D. The forklift 10b-2 is in a state where the tube 10D1 is contracted and the tube 10D2 is extended by the lifting device 10D. The forklift 10b-3 is in a state where the cylinders 10D1 and 10D2 are contracted by the lifting device 10D.

A mass damper mounting interface portion 10D4 is provided at a portion of the tube 10D1 that does not overlap with the tube 10D2, and a mass damper mounting interface portion 10D5 is provided at a portion of the tube 10D2 that does not overlap with the tube 10D3. The interface portion 10D4 and the interface portion 10D5 are a connection portion for attaching a mass damper that attaches the mass to the lifting device 10D via a spring or the like, or a part of the mass damper constituent portion. Here, the connecting portion means a structure such as a case or a bracket on which the mass damper is detachably mounted, and the part of the constituting portion means, for example, a support member using a spring or the like for supporting the mass body. It is a case or the like, and is configured to function as a mass damper by mounting a mass body.

In the unmanned forklift 10b-1, with the cylinders 10D1 and 10D2 extended, the mass damper connected to the interface section 10D4 and the mass damper connected to the interface section 10D5 suppress vibration of the lifting device 10D at the first frequency. Vibration is absorbed by the mass bodies of a pair of mass dampers as follows. In the unmanned forklift 10b-2, with the cylinder 10D1 extended, the mass damper connected to the interface unit 10D4 and the mass damper connected to the interface unit 10D5 cause the lifting device 10D to vibrate at a second frequency different from the first frequency. Vibrations are absorbed by the masses of the pair of mass dampers so that .

In the third embodiment, the vibration of the mast 22A can be suppressed by combining one set of mass dampers. Therefore, the influence of the inclination θ2 due to vehicle vibration can be suppressed.

(Other embodiments)
As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and design changes etc. within the scope of the present disclosure are also included. .

<Computer configuration>
FIG. 13 is a schematic block diagram showing the configuration of a computer according to at least one embodiment;
Computer 90 comprises processor 91 , main memory 92 , storage 93 and interface 94 .
The control device 13 and arithmetic device 11 described above are implemented in the computer 90 . The operation of each processing unit described above is stored in the storage 93 in the form of a program. The processor 91 reads out the program from the storage 93, develops it in the main memory 92, and executes the above processes according to the program. In addition, the processor 91 secures storage areas corresponding to the storage units described above in the main memory 92 according to the program. As for the acceleration calculation device 30, the operation of each processing unit described above may be realized by a separate computer having a similar configuration.

The program may be for realizing part of the functions that the computer 90 is caused to exhibit. For example, the program may function in combination with another program already stored in the storage or in combination with another program installed in another device. Note that in other embodiments, the computer may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLD include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array), and the like. In this case, part or all of the functions implemented by the processor may be implemented by the integrated circuit.

Examples of the storage 93 include HDD (Hard Disk Drive), SSD (Solid State Drive), magnetic disk, magneto-optical disk, CD-ROM (Compact Disc Read Only Memory), DVD-ROM (Digital Versatile Disc Read Only Memory). , semiconductor memory, and the like. The storage 93 may be an internal medium directly connected to the bus of the computer 90, or an external medium connected to the computer 90 via an interface 94 or communication line. Further, when this program is distributed to the computer 90 via a communication line, the computer 90 receiving the distribution may develop the program in the main memory 92 and execute the above process. In at least one embodiment, storage 93 is a non-transitory, tangible storage medium.

<Appendix>
The unmanned forklift (industrial vehicle) 10 described in each embodiment is understood as follows, for example.

(1) The industrial vehicle (unmanned forklift 10) according to the first aspect includes a traveling body 10A and a plurality of reflectors installed on the traveling body 10A via a lifting device 10D and installed in a traveling environment (warehouse 40). a laser sensor 10C1 that transmits a laser beam LA to a plate 50 and receives reflected light; an arithmetic unit 11 that calculates the position and orientation of the traveling body 10A based on the output of the laser sensor 10C1 to the reflector plate 50; A control device 13 for controlling the traveling of the traveling body 10A based on the calculation result of the position and the orientation, wherein the control device 13 controls at least the accuracy in controlling the traveling of the traveling body 10A and the acceleration of the traveling body 10A. and the height (H) of the laser sensor 10C1. 10A running is controlled. According to this aspect, it is possible to maintain the accuracy of travel control and obtain appropriate travel performance.

(2) The industrial vehicle (unmanned forklift 10) according to the second aspect is the industrial vehicle (unmanned forklift 10) of (1), wherein the models (first model 33, second model 34) Accuracy in control of running of the body 10A, acceleration of the running body 10A, height (H) of the laser sensor 10C1, velocity (V) of the running body 10A, and inclination of the laser sensor 10C1 (θ=θ1+θ2) represents a relationship with at least one of According to this aspect, the influence of speed and tilt can be taken into account.

(3) The industrial vehicle (unmanned forklift 10) according to the third aspect is the industrial vehicle (unmanned forklift 10) of (1) or (2), wherein the accuracy is at least stop positioning accuracy and travel locus accuracy. including one.

(4) An industrial vehicle (unmanned forklift 10) according to a fourth aspect is the industrial vehicle (unmanned forklift 10) of (1) to (3), wherein the upper limit of the acceleration is a constant that depends on the driving environment (K) is obtained by multiplying the required accuracy by the above model and using the above model. According to this aspect, uncertainties can be taken into account.

(5) An industrial vehicle (unmanned forklift 10) according to a fifth aspect is the industrial vehicle (unmanned forklift 10) of (1) to (4), wherein the lifting device 10D extends and retracts a plurality of overlapping cylinders. The laser sensor 10C1 has a structure in which the laser sensor 10C1 is moved up and down by moving, and mass damper attachment interfaces (interface portions 10D4 and 10D5) are provided in the portions where the two or more cylinders do not overlap. According to this aspect, the influence of vibration can be suppressed.

(6) The industrial vehicle (unmanned forklift 10) according to the sixth aspect is the industrial vehicle (unmanned forklift 10) of (1) to (5), which has a fork 21 and a vertically extending mast 22A. and a lift device 22 for lifting and lowering the fork 21 in the extending direction of the mast 22A, and attaching respective ends 61 and 62 of a turnbuckle 60 to the traveling body 10A and the mast 22A. It has interfaces (brackets 22D and 10A-2). According to this aspect, the influence of vibration can be suppressed.

DESCRIPTION OF SYMBOLS 1... Unmanned conveyance system 10... Unmanned forklift 10A... Traveling body 10B... Cargo-handling apparatus 10C... Laser scanner 10C1... Laser sensor 10D... Lifting apparatus 10D4, 10D5... Interface part 21... Fork 22... Lift device 22A... Mast 22D, 10A-2 Bracket 30 Acceleration calculator 31 Acceleration calculator 33 First model 34 Second model 40 Warehouse 50 Reflector 60 Turnbuckle LA Laser light

Claims (8)

a running body;
a laser sensor that is installed on the traveling body via an elevating device, transmits a laser beam to a plurality of reflectors installed in a traveling environment, and receives the reflected light;
a computing device that computes the position and orientation of the traveling object based on the output of the laser sensor;
a control device for controlling the traveling of the traveling body based on the calculation result of the position and orientation;
The control device controls at least the acceleration with which a predetermined required accuracy obtained using a model representing the relationship between the accuracy in the control of the running of the running body, the acceleration of the running body, and the height of the laser sensor is obtained. an industrial vehicle for controlling the traveling of the traveling body with the upper limit of 2. The model expresses the relationship among at least one of accuracy in control of running of the running body, acceleration of the running body, height of the laser sensor, and speed of the running body and inclination of the laser sensor. industrial vehicle described in . The industrial vehicle according to claim 1 or 2, wherein the accuracy includes at least one of stop positioning accuracy and travel locus accuracy. The upper limit of the acceleration is obtained using the model after multiplying the required accuracy by a constant that depends on the driving environment.
The industrial vehicle according to any one of claims 1 to 3. 5. The lifting device has a structure for lifting and lowering the laser sensor by expanding and contracting a plurality of overlapping cylinders, and has a mass damper mounting interface in each of the non-overlapping portions of the two or more cylinders. The industrial vehicle according to any one of claims 1 to 3. a fork;
a lift device that has a vertically extending mast and lifts and lowers the fork in the extending direction of the mast;
The industrial vehicle according to any one of claims 1 to 5, wherein the running body and the mast have mounting interfaces for each end of a turnbuckle. a running body;
a laser sensor that is installed on the traveling body via an elevating device, transmits a laser beam to a plurality of reflectors installed in a traveling environment, and receives the reflected light;
A method of controlling an industrial vehicle comprising:
calculating the position and orientation of the traveling object based on the output of the laser sensor;
A model representing at least the relationship among the accuracy in controlling the running of the running body, the acceleration of the running body, and the height of the laser sensor when the running of the running body is controlled based on the position and orientation calculation results. A control method for an industrial vehicle, comprising: controlling the traveling of the traveling body with the acceleration at which a predetermined required accuracy obtained using the above is set as an upper limit. a running body;
a laser sensor that is installed on the traveling body via an elevating device, transmits a laser beam to a plurality of reflectors installed in a traveling environment, and receives the reflected light;
When controlling an industrial vehicle equipped with
calculating the position and orientation of the traveling object based on the output of the laser sensor;
A model representing at least the relationship among the accuracy in controlling the running of the running body, the acceleration of the running body, and the height of the laser sensor when the running of the running body is controlled based on the position and orientation calculation results. A program for causing a computer to execute a step of controlling the running of the running body with the acceleration at which a predetermined required accuracy obtained using the above is set as an upper limit.

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