JP2017126286A - Mobile body, mobile body system, and method of calculating correction coefficient for mobile body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile body system which has high operation efficiency and is safe.SOLUTION: A mobile body 101 which is driven on the basis of instruction information created by an instruction information creation unit 111 includes: a storage unit 113 for storing a correction coefficient K which is a unique value; a reference position acquisition unit 114 for acquiring a reference position P1 of the mobile body 101; a virtual information acquisition unit 115 for acquiring a virtual position p1 and a specified velocity v1 and a target velocity v2 at a reference time point T1; and a calculation unit 116 for calculating a variable distance S by adding a distance in the case of changing velocity assuming a constant acceleration from the specified velocity v1 until reaching the target velocity v2 to a distance between the virtual position p1 and the reference position P1, and further subtracting a distance obtained by multiplying the target velocity v2 by the correction coefficient K.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a moving object, a moving object system, and a correction coefficient calculation method for the moving object, and in particular, a moving object that moves based on acceleration (including deceleration) according to a predetermined rule, a moving object system, and a moving object. The present invention relates to a method for calculating a body correction coefficient.

  Patent Document 1 discloses a traveling vehicle that controls a servo system including a traveling motor by a traveling control unit including a vibration suppression filter, obtains a traveling direction position of the traveling carriage by a position sensor, and feeds back to the servo system. ing. In this traveling vehicle, even if the stop position, speed, acceleration, and deceleration are changed during traveling by the vibration suppression filter, the input to the servo system does not change suddenly but gradually changes and can travel smoothly.

International Publication No. 2012/111193

  However, when the traveling vehicle travels according to the instruction information indicating the speed at a predetermined time, the traveling vehicle actually travels with a time delay with respect to the instruction information. It becomes longer than the distance based on the instruction information. Further, even if the traveling vehicle is caused to travel according to a command in which a vibration suppression filter is applied to the instruction information in order to make the traveling vehicle run smoothly, the shift distance becomes long.

  In this state, if the vehicle is decelerated by braking without considering the delay, the vehicle will go too far from the target position based on the instruction information, and it may collide with a vehicle traveling on the same track or enter a curve. Sufficient deceleration may not be achieved before. For this reason, a margin is ensured larger than necessary, and deceleration is started from the front more than necessary. Thus, securing a large margin is not preferable from the viewpoint of improving the operating rate of the traveling vehicle.

  The present invention has been made in view of the above problems, and a moving body such as a traveling vehicle capable of calculating a shift distance at high speed, a mobile body system, and a correction coefficient calculation of the moving body for calculating the shift distance. The purpose is to provide a method.

  In order to achieve the above object, a moving body according to the present invention is a moving body including an instruction information generating unit that generates instruction information indicating an instruction speed at a predetermined time point, and a drive unit that is driven based on the instruction information. Based on the instruction information, a storage unit that stores a correction coefficient K that is a value unique to the mobile body, a reference position acquisition unit that acquires a reference position P1 that is information related to the position of the mobile body at the reference time point T1. A virtual information acquisition unit that acquires the virtual position p1, the instruction speed v1, and the target speed v2 at the reference time point T1, and the acceleration from the instruction speed v1 to the target speed v2 at the distance between the virtual position p1 and the reference position P1. And a calculation unit for calculating the shift distance S by adding the distance when the speed is changed with the constant being constant, and further subtracting the distance obtained by multiplying the target speed v2 by the correction coefficient K. The features.

  According to this, the shift distance S until the target speed is reached can be calculated relatively accurately by simple calculation without performing complicated calculations such as obtaining the shift distance S by integrating the expected speed change curve. It becomes possible to do. Therefore, the margin for the shift start timing can be reduced, and the operating efficiency of the moving body can be improved.

  The reference position acquisition unit may acquire the reference position P1 based on the actual position of the moving body.

  Further, the reference position acquisition unit may acquire a reference position P1 of the moving body based on an encoder provided in the driving unit, and detects a detected object provided along a trajectory along which the moving body moves. Thus, the reference position P1 of the moving body may be acquired.

  According to these, since the actual (absolute) movement position of the moving body can be accurately acquired, the actual (absolute) position of the moving body when the target speed is reached is accurately grasped. It becomes possible.

  Further, the reference position acquisition unit may acquire the reference position P1 of the moving body by applying a transfer function to the instruction information.

  According to this, even when there is no sensor for detecting the position of the moving body or even in the case of a failure, the actual moving position of the moving body can be obtained relatively accurately, and the moving body at the time of reaching the target speed can be obtained. It becomes possible to grasp the actual position relatively accurately.

  Moreover, the said moving body may move along a rail.

  According to this, since the moving state of the moving body with respect to the rail is stabilized, it becomes possible to calculate a more accurate shift distance S.

  In order to achieve the above object, a mobile system according to the present invention is a mobile system including a mobile body and a host controller that controls the mobile body, and includes instruction information indicating an instruction speed at a predetermined time point. An instruction information creation unit to be created, a drive unit that drives the moving body based on the instruction information, a storage unit that stores a correction coefficient K that is a value unique to the moving body, and a position of the moving body at a reference time point T1 A reference position acquisition unit that acquires a reference position P1 that is information on the virtual position p1, a virtual position acquisition unit that acquires a virtual position p1, a command speed v1, and a target speed v2 at a reference time point T1 based on the instruction information; and a virtual position p1 Is added to the distance between the command speed v1 and the reference position P1, and the distance when the speed is changed with the acceleration from reaching the target speed v2 to the target speed v2 is constant. Characterized in that it comprises a calculation unit that calculates a shift distance S by adding a distance obtained by multiplying the correction coefficient K.

  According to this, the shift distance S until the target speed is reached can be calculated relatively accurately by simple calculation without performing complicated calculations such as obtaining the shift distance S by integrating the expected speed change curve. It becomes possible to do. Therefore, the margin for the shift start timing can be reduced, and the operating efficiency of the moving body can be improved.

  In order to achieve the above object, the correction coefficient calculation method for a moving body according to the present invention is a distance in which the moving body is moved according to the instruction information until it reaches the target speed v2 from the instruction speed v1. And a correction coefficient K unique to the moving object is calculated by calculating backward from the obtained value.

  As a result, the correction coefficient K specific to the moving body can be calculated, which can contribute to the accurate calculation of the shift distance S of the moving body.

  In addition, executing the program for making a computer perform each process which the said mobile body, mobile body system, and the correction | amendment coefficient calculation method of a mobile body include also corresponds to implementation of this invention. Of course, the implementation of the recording medium in which the program is recorded also corresponds to the implementation of the present invention.

  According to the present invention, the shift distance of the moving body can be calculated at high speed by a simple process, and the operating efficiency of the moving body can be improved.

FIG. 1 is a diagram schematically illustrating a mobile system. FIG. 2 is a block diagram showing the functional unit of the transport vehicle together with the mechanism unit. FIG. 3 is a graph of distance (position) with respect to time indicating the instruction information (solid line) and the actual movement (broken line) of the moving object. FIG. 4 is a graph of speed with respect to time showing the calculation result (solid line) and the actual movement of the moving body (broken line). FIG. 5 is a flowchart showing the flow of information processing. FIG. 6 is a flowchart for calculating the correction coefficient.

  Next, an embodiment of a moving body, a moving body system, and a moving body correction coefficient calculation method according to the present invention will be described with reference to the drawings. The following embodiments are merely examples of the moving body, the moving body system, and the correction coefficient calculation method for the moving body according to the present invention. Therefore, the scope of the present invention is defined by the wording of the claims with reference to the following embodiments, and is not limited to the following embodiments. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept of the present invention are not necessarily required to achieve the object of the present invention. It will be described as constituting a preferred form.

  In addition, the drawings are schematic diagrams in which emphasis, omission, and ratio adjustment are appropriately performed to show the present invention, and may differ from actual shapes, positional relationships, and ratios.

  FIG. 1 is a diagram schematically illustrating a mobile system.

  As shown in FIG. 1, the mobile system 100 is a system that includes a mobile body 101 and a host controller 102 that controls the mobile body 101. In the case of the present embodiment, the mobile body 101 is a traveling vehicle capable of transporting a load from a predetermined place to another place, and the mobile system 100 as a whole is a transport system that transports the load.

  The host controller 102 is a computer system that manages the movement of the moving body 101, such as the movement of the moving body 101, the transporting location and the receiving location of luggage.

  In the case of the present embodiment, the host controller 102 transmits so-called from-to information, which is information indicating the destination of delivery and the destination of the package, to the mobile unit 101 via communication means such as a wired or wireless LAN, The operation of the moving body 101 is controlled.

  The mobile body 101 is a device that can transport a package from one place to another based on an external command such as the host controller 102, for example, from-to-information. In the case of the present embodiment, the moving body 101 is a traveling vehicle that moves along a rail 110 provided on a ceiling, a floor, or the like, and is a rack that can store luggage or a product that is processed by processing luggage or the like. Is provided with a transfer device capable of transferring a load between a production facility (not shown) for producing the goods and the moving body 101.

  The rail 110 is a rail for determining a moving path of the moving body 101 in advance. The rail 110 is not limited to a specific member such as a rail, but may be a line drawn on the floor. Note that the moving body 101 is not limited to moving along the rail 110, but may move along a route virtually formed by software.

  FIG. 2 is a block diagram showing the functional unit of the transport vehicle together with the mechanism unit.

  As shown in the figure, the moving body 101 is a car capable of transporting a load along a predetermined route such as a rail 110, and includes an instruction information creating unit 111, a driving unit 112, and a storage unit 113. A reference position acquisition unit 114, a virtual information acquisition unit 115, and a calculation unit 116. In addition, the mobile unit 101 includes a communication unit 117 that can communicate with the host controller 102 and the like.

  In the case of the present embodiment, the mobile unit 101 includes a computer that processes information by executing software, and includes an instruction information creation unit 111, a part of the drive unit 112, a storage unit 113, and a reference position acquisition. The unit 114, the virtual information acquisition unit 115, and the calculation unit 116 function as software modules executed on the computer. Note that some or all of these may function as hardware.

  The instruction information creation unit 111 is a processing unit that creates instruction information indicating the instruction speed of the mobile object 101 at a predetermined time. In the case of the present embodiment, the instruction information creating unit 111 determines the instruction speed at each time point arranged at a predetermined time interval based on a command acquired from the host controller 102 via the communication unit 117, for example, from-to-information. Is created as instruction information. Here, since the time, speed, distance, and acceleration have a certain relationship, the instruction information only needs to indicate the instruction speed at a predetermined time point based on at least any two of them. The instruction information creating unit 111 may accumulate the history and create instruction information including the virtual position of the moving body 101 based on the result.

  The drive unit 112 includes a processing unit that moves the moving body 101 based on the instruction information, and a motor. In the case of the present embodiment, the drive unit 112 includes a moving servo motor, wheels that are connected to the servo motor and roll in contact with the rail 110, a movement control unit that controls the servo motor, and the like. Furthermore, the drive unit 112 includes an encoder for acquiring a reference position. In the case where the moving body 101 does not move along the rail 110 but moves on the floor surface, the drive unit 112 may further include a servo motor for steering. Further, the position sensor for acquiring the reference position is not limited to the encoder, but may be a sensor for detecting a detection object provided at a predetermined interval along the track, a laser distance meter, a magnetic linear sensor, or the like.

  The storage unit 113 is a device that stores a correction coefficient K, which is a value unique to the moving object 101 acquired by prior measurement or the like. Specifically, the storage unit 113 is a hard disk or a flash memory.

  The reference position acquisition unit 114 is a processing unit that acquires a reference position P1 that is information related to the position of the moving object 101 at the reference time point T1. In the case of the present embodiment, the reference position acquisition unit 114 acquires the actual position of the moving body 101 obtained based on the output information from the encoder provided in the drive unit 112 as the reference position P1. Note that the reference position acquisition unit 114 may acquire the actual position of the moving body 101 as the reference position P1 based on the above-described sensor for detecting the detected object, a laser distance meter, a magnetic linear sensor, or the like.

  The reference position acquisition unit 114 does not acquire the position of the moving body 101 by sensing, but acquires a predicted value obtained by calculation based on the instruction information generated by the instruction information generation unit 111 as the reference position P1 of the moving body. It doesn't matter. Specifically, for example, the reference position P1 may be acquired by applying a transfer function to the instruction information.

  The virtual information acquisition unit 115 is a processing unit that acquires the virtual position p1 and the instruction speed v1 at the reference time point T1 based on the instruction information, and further acquires the target speed v2.

  The calculation unit 116 maintains a constant acceleration (including acceleration and deceleration) until the target speed v2 is reached from the command speed v1 to the distance e between the virtual position p1 acquired by the virtual information acquisition unit 115 and the reference position P1. Is a processing unit that calculates the shift distance S by adding the distance when the speed is changed and further subtracting the distance obtained by multiplying the target speed v2 by the correction coefficient K. This calculation is expressed as follows.

  Shift distance S = p1-P1 + ((v1) ^ 2- (v2) ^ 2) / 2a- (v2) K

  Here, a is an acceleration arbitrarily determined in advance based on the performance of the moving body 101. “^” Represents a power.

  Next, an example of specific information processing in the moving body 101 will be described with reference to FIGS.

  FIG. 3 is a graph of distance (position) with respect to time indicating the instruction information (solid line) and the actual movement (broken line) of the moving object.

  FIG. 4 is a graph of speed with respect to time showing the calculation result (solid line) and the actual movement of the moving body (broken line).

  FIG. 5 is a flowchart showing the flow of information processing.

  First, a command for receiving a package at a predetermined position is received from the host controller 102 (S101). Here, the predetermined position is, for example, a carry-out position of a load such as a rack in which the load is stored and a production facility.

  Next, the instruction information creation unit 111 starts creating new instruction information for driving the drive unit 112 based on the command of the host controller 102 (S102).

  Here, when there is a curve up to a predetermined position to be reached, the virtual information acquisition unit 115 acquires the speed for safely moving the curve as the target speed v2 from a constraint condition that exists separately (S103). ).

  Next, the reference position acquisition unit 114 acquires the current position of the moving body 101 as the reference position P1 using the current time as the reference time T1. Here, the reference position P1 may be not only the absolute position with respect to the rail 110 but also the distance to the curve.

  Further, the virtual information acquisition unit 115 acquires the virtual position p1 at the reference time T1 and the current instruction speed v1 based on the instruction information created in advance (S105).

  Next, the calculation unit 116 calculates according to the above-described mathematical formula, and calculates the shift distance S (S106). Here, since the shift distance S can be calculated by a simple mathematical formula, a predicted curve that is a curve that predicts the actual movement of the moving body 101 is created, and the shift distance S is calculated by integrating the predicted curve. The shift distance S can be calculated in a short time.

  Next, the difference between the distance to the curve and the shift distance S is calculated, and if it is greater than or equal to a predetermined threshold (S107: Y), the mobile body 101 is tried to accelerate (S108), and the speed is changed again based on the speed after acceleration. The distance S is calculated. It should be noted that acceleration is not performed when the moving body 101 has already moved at the prescribed maximum speed.

  If the difference between the distance to the curve and the shift distance S is less than a predetermined threshold (S107: N), the current speed of the moving body 101 is maintained, and deceleration is started just before the shift distance S from the curve.

  According to the moving body 101 described above, even if the shift distance S is repeatedly calculated at intervals of the order of milliseconds, for example, the shift distance S can be calculated without greatly affecting other calculations. The calculated shift distance S is a value close to the distance traveled when the mobile body 101 actually shifts. Therefore, since the moving body 101 can be accelerated and moved at the maximum speed from a predetermined position such as a curve to the position before the shift distance S without providing a large margin, the operating efficiency of the moving body 101 can be improved. It becomes.

  Next, an example of a correction coefficient calculation method will be described.

  FIG. 6 is a flowchart for calculating the correction coefficient.

  First, the moving body 101 is moved by v1 on a predetermined trajectory (rail) (S201). Next, a shift is started so that the speed becomes v2 when the moving body 101 reaches a predetermined position (S202). Here, the acceleration a at the time of shifting from v1 to v2 is determined in advance based on the performance of the moving body 101 and the presence / absence of the loaded luggage. Accordingly, there may be a plurality of accelerations a for one moving body 101. Further, the acceleration a may be a function that changes with time.

  Next, when the target speed v2 is reached, the moving distance from the predetermined position of the moving body 101 is measured.

  As described above, the correction coefficient K is calculated based on the set value and the measurement result. When there are a plurality of patterns of acceleration a, the correction coefficient K is calculated by moving the moving body 101 according to the pattern of acceleration a. If the correction coefficient K depends on the target speed v2, the correction coefficient K may be calculated based on a plurality of different target speeds v2.

  The above correction coefficient calculation method is preferably performed after the mobile system 100 is installed. Further, by periodically calculating the correction coefficient K, it is possible to cope with the secular change of the mobile system 100 and to calculate the accurate shift distance S over a long period of time.

  The present invention is not limited to the above embodiment. For example, another embodiment realized by arbitrarily combining the components described in this specification and excluding some of the components may be used as an embodiment of the present invention. In addition, the present invention includes modifications obtained by making various modifications conceivable by those skilled in the art without departing from the gist of the present invention, that is, the meaning of the words described in the claims. It is.

  In the mobile system 100, the instruction information creation unit 111, a part of the drive unit 112, the storage unit 113, the reference position acquisition unit 114, the virtual information acquisition unit 115, and the calculation unit 116 are all included in the mobile unit 101. None of these may be processed by the host controller 102 or another computer.

  Further, the moving body 101 can be exemplified not only a traveling vehicle that runs on the floor surface, but also an overhead traveling carriage, a stacker crane, an automatic guided vehicle that autonomously moves on the floor surface, and the like. Further, the moving body 101 may be a lifting platform that moves up and down along a mast in a stacker crane, an arm that extends and contracts for transferring a load, a fork, and the like.

  Further, although the case of deceleration has been described as an example, the deceleration includes a case where the target speed v2 is zero, that is, a stop. The present invention is also applicable to acceleration, acceleration and deceleration, or deceleration and acceleration. Furthermore, the present invention can also be applied to a case where the mobile body 101 reciprocates, that is, a case where the mobile body 101 decelerates to stop and accelerates in the opposite direction.

  In addition, the position where the target speed v2 is reached is described as immediately before the curve. However, when the moving body is moved after a predetermined distance from the preceding moving body, the speed of the preceding vehicle becomes the target speed v2, so the target speed v2 is reached. Is not constant, and the position changes every moment. Therefore, although the shift distance S is calculated many times according to the change, according to the present invention, the shift distance S can be easily calculated.

  The present invention can be applied to a moving body that repeatedly accelerates and decelerates, and can be applied to a transport system that transports loads, an automatic warehouse that stores and transports loads in a predetermined position, an unmanned transport vehicle that transports loads unattended. it can.

DESCRIPTION OF SYMBOLS 100 Mobile body system 101 Mobile body 102 Host controller 110 Rail 111 Instruction information creation part 112 Drive part 113 Storage part 114 Reference position acquisition part 115 Virtual information acquisition part 116 Calculation part 117 Communication part

Claims (8)

A moving body comprising an instruction information creating unit that creates instruction information indicating an instruction speed at a predetermined time point, and a drive unit that is driven based on the instruction information,
A storage unit that stores a correction coefficient that is a value unique to the moving body;
A reference position acquisition unit that acquires a reference position that is information on the position of the moving object at the reference time point;
A virtual information acquisition unit that acquires a virtual position, an instruction speed, and a target speed at a reference time point based on the instruction information;
Add the distance when the speed is changed with the acceleration from reaching the target speed to the target speed constant to the distance between the virtual position and the reference position, and further subtract the distance obtained by multiplying the target speed by the correction coefficient. And a calculating unit that calculates a shift distance. The moving body according to claim 1, wherein the reference position acquisition unit acquires a reference position based on an actual position of the moving body. The reference position acquisition unit
The moving body according to claim 2, wherein a reference position of the moving body is acquired based on an encoder provided in the driving unit. The reference position acquisition unit
The moving body according to claim 2, wherein a reference position of the moving body is acquired by detecting a detected body provided along a trajectory along which the moving body moves. The reference position acquisition unit
The mobile body according to claim 1, wherein a predicted value obtained by calculation based on the instruction information is acquired as a reference position of the mobile body. The said moving body is a moving body as described in any one of Claims 1-5 which moves along a rail. A mobile system comprising a mobile and a host controller for controlling the mobile,
An instruction information creating unit for creating instruction information indicating an instruction speed at a predetermined time;
A drive unit for driving the movable body based on the instruction information;
A storage unit that stores a correction coefficient that is a value unique to the moving body;
A reference position acquisition unit that acquires a reference position that is information on the position of the moving object at the reference time point;
A virtual information acquisition unit that acquires a virtual position, an instruction speed, and a target speed at a reference time point based on the instruction information;
Add the distance when the speed is changed with the acceleration from reaching the target speed to the target speed constant to the distance between the virtual position and the reference position, and further add the distance obtained by multiplying the target speed by the correction coefficient And a calculating unit for calculating a shift distance. The moving body according to any one of claims 1 to 6 is moved according to the instruction information until reaching the target speed from the instruction speed, the distance actually moved is measured, and the calculated value is calculated backward to calculate the distance A method for calculating a correction coefficient for a moving body, which calculates a correction coefficient specific to the moving body.

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