JP2019059460A - Robot for load-carrying platform conveyance - Google Patents

Abstract

To provide a robot for load-carrying platform conveyance which can stably lift up and convey a load-carrying platform, and only needs the narrow work space.SOLUTION: A robot R includes: a body 1; a pair of crawler devices 2, 2 which is provided in the body 1 and can travel in two directions; and lifters 70 which are provided in 4 corners of the body. Each of the lifters 70 includes a pedestal 71 and an actuator 73 which makes the pedestal 71 ascend/descend. The robot R lifts up a cargo 100 (load-carrying platform) by making the pedestal 71 ascend in the state of crawling under the cargo 100, and conveys the cargo 100 to the destination location with driving of the crawler devices 2, 2.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a robot for transporting a cargo bed or the like.

As disclosed in Patent Document 1, a forklift lifts a loading platform such as a cargo loaded thereon and transports it to a destination.
The robot disclosed in Patent Document 2 has a traction unit, and travels by removably connecting the traction unit to a wheeled loading platform. The loading platform is pulled by the robot and moves following the robot.
The robot disclosed in Patent Documents 3 and 4 has a loading platform, and loads the load directly on the loading platform and transfers it.
The robot disclosed in Patent Document 5 includes a crawler device capable of traveling in two directions as in the embodiment of the present application.

JP 2000-226196 A JP-A-9-254788 JP, 2008-179187, A Unexamined-Japanese-Patent No. 2010-235082 WO 2017/006909 gazette

The forklift disclosed in Patent Document 1 can carry a load while being loaded on a loading platform, and thus does not require lifting and unloading operations. However, since the loading platform is lifted in a cantilever state by a fork, the forklift is made large to transfer It needs to be stabilized. As a result, a large work space is required.
In the robot disclosed in Patent Document 2, the transport of the loading platform is unstable because it only pulls the loading platform with wheels. Moreover, the operation | work which connects a tow part detachably to a loading platform is also complicated.
In the robots disclosed in Patent Documents 3 and 4, since the load is directly placed on the loading platform of the robot, the work space may be narrow, but the loading and unloading operation of the load is complicated.
Although the robot disclosed in Patent Document 5 is not for transferring a load, even if the load can be transferred, the same problems as those in Patent Documents 3 and 4 occur.

The present invention has been made to solve the above problems, and is a robot for transporting a loading platform, comprising: a body, a traveling device provided in the body, and the body provided with three or more to lift the loading platform And a controller provided on the body and controlling the traveling device and the lifter.
According to the above configuration, since the package is transported by the robot together with the loading platform, the package can be transported without performing the lifting and lowering operation on the robot. The space required for transportation can be reduced because it can be buried under the loading platform and lifted. Since the robot and the platform can be linked and canceled only by raising and lowering the lift, the workability is good.
By using three or more lifters, the load can be dispersed, the load on each lifter can be reduced, and the loading platform can be stably lifted and transported.

Preferably, the body has a flat rectangular shape, and the lifters are provided at four corresponding to four corners of the body.
According to the above configuration, the loading platform can be lifted and transported more stably.

  In one aspect of the present invention, each of the lifters has an independent stand for receiving a load from the bed and an actuator for raising and lowering the stand.

In the above aspect, preferably, each of the three or more lifters includes load detection means for detecting a load received by the pedestal from the cargo platform, and the controller controls the cargo platform by the three or more lifters. In the lifted state, based on load information from the load detection means of the three or more lifters, the deviation of the load received by the pedestals of the three or more lifters is detected.
According to the above configuration, when there is a large deviation in the load distribution of the load placed on the loading platform, this deviation can be detected.

  The load detection means may be a load cell incorporated below the pedestal, or may be load current detection means for detecting the load current of the actuator in the process of lifting the loading platform.

Preferably, the body is provided with position detection means for detecting the relative position of the body with respect to the loading platform, and the controller is configured to bias the load received by the pedestals of the plurality of three or more lifters. When it is determined that the value exceeds the allowable range, the pedestal is lowered by moving the three or more lifters away from the loading platform, and further based on the load information and the position information from the position detection means. By controlling the traveling device, the body is moved to the correction position where the load deviation falls within the allowable range, and after the body reaches the correction position, the plurality of three or more lifters are moved. The control lifts the platform again.
According to the above configuration, even if there is a large deviation in the load distribution of the load placed on the loading platform, the load position can be reduced or eliminated by correcting the robot position, and the loading platform can be stably lifted and transported. Can.

Preferably, when the controller determines that the load deviation received by the pedestals of the three or more lifters exceeds the allowable range, the controller cancels the load deviation so as to fall within the allowable range. Selectively control one or more lifters.
According to the above configuration, even when there is a large deviation in the load distribution of the load placed on the platform, the deviation of the load can be reduced or eliminated, and the platform can be stably lifted and transported.

In one specific example of control for reducing or eliminating the load deviation, the controller calculates the difference between the maximum value and the minimum value of the load carried by the three or more lifters as the load deviation. And, when it is determined that the difference between the maximum value and the minimum value exceeds the allowable range, the lifter corresponding to the table is selectively controlled to lower the table bearing the load of at least the maximum value. .
As another specific example of control for reduction or elimination of the load deviation, the actuator of the lifter is PWM controlled, and the controller is a load that the pedestals of the three or more lifters bear as the load deviation. The difference between the maximum value and the minimum value is calculated, and when it is determined that the difference between the maximum value and the minimum value exceeds the allowable range, the duty ratio of the actuator corresponding to the bearing bearing the load of at least the maximum value is Lower than the duty ratio corresponding to other pedestals.

In another aspect of the present invention, the three or more lifters are connected at their upper ends to a single flat common receiving plate, and lift the loading platform through the receiving plate.
According to the above configuration, even if the bottom portion of the loading platform is not flat and, for example, a large number of holes are formed or it is reticulated, the loading platform can be stably lifted by the flat wide receiving plate.

Preferably, each of the three or more lifters has lift height detection means, and the controller lifts the loading platform based on lift height information from the lift height detection means. The lifters are controlled such that the deviation of the lift heights of three or more lifters falls within an allowable range.
According to the above configuration, the loading platform can be lifted with its bottom portion kept horizontal. In the case of using a common receiving plate, the deviation of the lift height within an allowable range causes an excessive load on any of the three or more lifter actuators mutually regulated by the common receiving plate. Can also be avoided.

Preferably, the controller monitors the lift height of each of the three or more lifters, and the deviation between the lift height of the monitored lifter and the minimum value of the lift heights of the three or more lifters is a first threshold If it is larger, stop and wait until the deviation falls within the first threshold. According to this configuration, the lift height can be adjusted with relatively simple control.
More preferably, the controller sets a second threshold larger than the first threshold, and the deviation between the lift height of the lifter to be monitored and the minimum lift height of the three or more lifters is greater than the second threshold If it is large, the lifter to be monitored is lowered until the deviation falls within the second threshold. According to this configuration, it is possible to quickly reduce the deviation of the lift height.

Preferably, the traveling device includes a pair of crawler devices extending in a first direction and spaced apart from each other in a second direction orthogonal to the first direction, each of the pair of crawler devices being A crawler unit supported on the body so as to be rotatable about a first rotation axis extending in a first direction, each crawler unit having a support extending along the first rotation axis, and the support And a pair of crawler portions disposed on both sides of the first rotation axis, and each of the crawler devices is a rolling device that rotates the crawler unit around the first rotation axis. It has a driving mechanism for traveling, and a driving mechanism for crawler traveling which simultaneously drives the pair of crawler units.
According to the above configuration, since the traveling device is a crawler device, the contact area is wider than that of the wheeled traveling device, and slippage can be suppressed. Further, in the crawler traveling by the drive of the crawler unit, it is possible to easily get over a ditch or a small obstacle as in a usual crawler traveling device. Since the entire crawler unit rolls, rolling travel can be carried out with a sufficiently large diameter, and it is possible to easily get over a ditch or a small obstacle. As a result, the loading platform can be stably transported. Moreover, the direction change is easy by using the crawler device which can travel in two directions.

  According to the present invention, the work space can be narrowed, the loading platform can be stably transported, and the workability before and after transportation can be enhanced.

FIG. 1 is a schematic plan view of a robot for transporting a loading space according to a first embodiment of the present invention. It is a schematic side view of the said robot seen from the A direction in FIG. It is a plane sectional view of the crawler device with which the above-mentioned robot is equipped. It is a side view of the lifter with which the above-mentioned robot is equipped, (A) shows the state where a pedestal is in a lower limit position, (B) shows the state where a pedestal is in an upper limit position. It is a schematic side view which shows the state in which the said robot has got under the cargo. It is a schematic side view which shows the state which the said robot lifted the cargo. It is a flow chart which shows an example of cargo lift control. It is a bottom view which shows arrangement | positioning of the optical sensor in case the said robot drive | works by a line trace system. It is a schematic plan view of a robot for conveyance of a loading platform according to a second embodiment of the present invention. It is a schematic side view of the robot of the second embodiment, (A) shows a state in which the receiving plate is at the lower limit position, (B) shows a state in which the receiving plate is at the upper limit position. It is a side view showing a receiving plate and a lifter in the second embodiment. It is a flowchart which shows the cargo lifting control in said 2nd Embodiment. It is a flowchart which shows the unloading control in said 2nd Embodiment.

  Hereinafter, a robot (load transport robot) according to a first embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, an X direction (first direction) and a Y direction (second direction) orthogonal to each other are determined.

  As shown in FIGS. 1 and 2, the robot R includes a body 1, a pair of crawler devices 2 (traveling devices), and four lifters 70. The body 1 has a flat rectangular shape, and the body 1 includes a controller 1a (only shown in FIG. 2) including a microcomputer for controlling the crawler device 2 and the lifter 70 etc., an interface, a transmitter / receiver, a battery etc. Not shown) is built in.

  The pair of crawler devices 2 can travel in two directions, and each has a long and thin cylindrical crawler unit 3 extending in the X direction. The pair of crawler units 3 are separated from each other in the Y direction. Each crawler unit 3 is rotatably supported by the body 1 about a first rotation axis L1 extending in the X direction by a pair of brackets 4 projecting from the body 1 in the Y direction. Since the crawler unit 3 is disposed to the side of the body 1, even if the body 1 is lowered, the diameter of the crawler unit 3 can be increased.

  As shown in FIG. 3, the crawler unit 3 of each crawler device 2 includes a support 10, a pair of crawler portions 20 A and 20 B provided on the support 10, and a pair of support units provided on the support 10. It has ground structure 30A, 30B.

  The support 10 is parallel to each other, extends in the X direction (the direction of the first rotation axis L1), and has a pair of elongated support plates 11, 11 opposite to each other with the first rotation axis L1 interposed therebetween. The driving shaft 12 is rotatably connected to one end of the support shaft 11, the driven shaft 13 is connected to the other end of the support plates 11 and 11, and the fixing plate 14 is fixed to an intermediate portion of the support plates 11 and 11. And.

  The central axes L2 and L2 'of the driving side shaft 12 and the driven side shaft 13 extend perpendicularly to the first rotation axis L1 and in parallel with each other, and the rotational axes of the sprocket wheels 21 and 22 described later (second Provided as a rotational axis).

  The pair of crawler portions 20A and 20B are disposed to face each other with the first rotation axis L1 interposed therebetween. Each of the crawler units 20A and 20B includes a driving sprocket wheel 21 (wheel) and a driven sprocket wheel 22 (wheel) separated in the direction of the first rotation axis L1, and a chain 23 (see FIG. And a plurality of grounding members 24 made of, for example, rubber fixed at equal intervals to the chain 23.

The driving sprocket wheel 21 of one crawler unit 20A is directly fixed to the driving shaft 12. The driving sprocket wheel 21 of the other crawler unit 20B is fixed to the driving shaft 12 via a bevel gear 42b described later. There is.
The driven sprocket wheels 22, 22 of the pair of crawler units 20A, 20B are rotatably supported by the driven shaft 13.

  Each of the pair of ground structures 30A, 30B has a plurality of (five in the present embodiment) ground plates 31 arranged at intervals in the direction of the first rotation axis L1. The ground plate 31 is made of, for example, rubber, is fixed to the outer surface of the support plate 11, and protrudes in the direction of the second rotation axis L2, L2 at right angles to the support plate 11.

As shown in FIG. 2, the outer surfaces of the ground members 24 of the pair of crawler portions 20A and 20B and the outer surfaces of the ground plates 31 of the pair of ground structures 30A and 30B are arc-shaped. In the above, it is disposed along a virtual cylindrical surface centered on the first rotation axis L1. A notch 31 a is formed on the outer surface of the ground plate 31.
The grounding structures 30A and 30B provide the crawler unit 3 with a dead zone of a predetermined range.

The crawler unit 3 is rotatably supported by the pair of brackets 4 via a first rotation shaft 41 and a second rotation shaft 42 disposed on the first rotation axis L1.
The outer end of the first rotating shaft 41 is rotatably supported by one of the brackets 4 (right side in FIG. 3). The inner end of the first rotating shaft 41 is rotatably supported by the fixed plate 14. A bevel gear 42 a is fixed to an inner end portion of the first rotation shaft 41, and the bevel gear 42 a meshes with a bevel gear 42 b fixed to the drive side shaft 12. The first rotating shaft 41 penetrates the driven shaft 13 at an intermediate portion thereof. In this penetration state, rotation of the first rotating shaft 42 about the first rotation axis L1 is permitted.

  The outer end portion of the first rotary shaft 41 is connected to the crawler travel drive mechanism 50 (travel drive means). The crawler traveling drive mechanism 50 has a motor 51 fixed to the bracket 4 and a power transmission mechanism 55. The motor 51 can rotate in forward and reverse directions. The power transmission mechanism 55 includes timing pulleys 55a and 55b, and a timing belt 55c bridged over the timing pulleys 55a and 55b. One timing pulley 55 a is fixed to the output shaft of the motor 51, and the other timing pulley 55 b is fixed to the first rotating shaft 41.

  The rotational torque of the motor 51 is transmitted to the first rotary shaft 41 through the power transmission mechanism 55, and further transmitted to the driving sprocket wheel 21 of the crawler unit 20B through the bevel gears 42a and 42b, and further through the driving shaft 12. It is also transmitted to the driving sprocket wheel 21 of the crawler unit 20A. Thus, the pair of crawler units 20A and 20B are simultaneously driven in the same direction at the same speed.

  The outer end of the second rotary shaft 42 is rotatably supported by the other (left side in FIG. 3) bracket 4. The inner end of the second rotary shaft 42 is connected to the drive shaft 12. In this connection state, rotation of the drive side shaft 12 about the second rotation axis L2 is permitted.

  The outer end portion of the second rotary shaft 42 is connected to a rolling travel drive mechanism 60 (travel drive means). The rolling travel drive mechanism 60 includes a motor 61 fixed to the bracket 4 and a power transmission mechanism 65. The motor 61 can rotate in forward and reverse directions. The power transmission mechanism 65 has timing pulleys 65a and 65b and a timing belt 65c bridged over the timing pulleys 65a and 65b. One timing pulley 65 a is fixed to the output shaft of the motor 61, and the other timing pulley 65 b is fixed to the second rotating shaft 42.

  The rotational torque of the motor 61 is transmitted to the second rotary shaft 42 through the power transmission mechanism 65, and is further transmitted to the support 10 through the driving shaft 12. Therefore, the entire crawler unit 3 centers on the first rotational axis L1. Turn (roll).

  The traveling of the robot R by the pair of crawler devices 2 and 2 will be described. In each crawler device 2, when the motor 51 of the crawler traveling drive mechanism 50 is driven in a state where the pair of crawler units 20A and 20B are grounded, as described above, the crawler units 20A and 20B simultaneously rotate in the same direction. Thus, the crawler device 2 can travel in the X direction (crawler travel).

  By rotating the motors 51, 51 of the pair of crawler devices 2, 2 at the same speed in the same direction, the robot R can move straight in the X direction. By making the rotational speeds of the motors 51, 51 different, the robot R can also travel in a curve. In addition, by rotating the motors 51, 51 at different speeds and at the same speed, the robot R can also turn on the spot (turning on the ground).

  When the motor 61 of the crawler device 2 is driven, the crawler unit 5 rotates (rolls) about the first rotation axis L1 as described above. When the pair of crawler devices 2 simultaneously roll in the same direction at the same speed, the robot R can travel straight in the Y direction (rolling travel).

  The robot R can also switch the traveling direction to a right angle without turning on the ground by switching from one of the crawler traveling mode and the rolling traveling mode to the other.

  By simultaneously driving the motors 51 and 61 of the crawler device 2 and controlling the rotation speed and the rotation direction, the robot R can also travel linearly in any oblique direction (diagonal travel). In this oblique traveling, the upper and lower portions of the crawler units 20A and 20B frequently reversely rotate due to the rolling of the crawler unit 3, while the dead zone of the crawler unit 3 is grounded (the ground plate 31 of the grounding structure 30 is grounded) While the motor 51 is switched).

  In the crawler traveling, the crawler unit 3 does not land in the dead zone, and at least one of the pair of crawlers 20A and 20B needs to be in contact with the ground so that it can travel by driving the crawlers 20A and 20B. Therefore, the crawler unit 3 travels by driving the rolling drive mechanism 60 based on the posture information of the crawler unit 3 from the posture detection sensor (not shown) after the end of the rolling travel or oblique travel, or before the start of the crawler travel. It is preferable to perform posture control so as to be in a drivable posture in which the vehicle is grounded in the possible zone.

  As shown in FIG. 1, the four lifters 70 described above are respectively installed at four corners of the body 1. As shown in FIG. 4, the lifters 70 are independent of each other, and each have a pedestal 71, a bracket 72, and an actuator 73 supported by the bracket 72 to raise and lower the pedestal 71. The bracket 72 is fixed to the lower surface of the upper plate of the body 1.

  The actuator 73 is a motor 75 fixed to the bracket 72, a lift rod 76 vertically extended and supported vertically movably by the bracket 71, and a power for decelerating the rotation of the motor 75 and converting it into the lift motion of the lift rod 76. And a transmission mechanism 77. The pedestal 71 is attached to the upper end of the lift rod 76 via a load cell 78 (load detection means).

  The power transmission mechanism 77 includes a worm 77a rotatably supported by the bracket 72 and coupled to the output shaft of the motor 75 via a reduction gear, a worm wheel 77b meshing with the worm 77a, and a pinion 77c coaxial with the worm wheel 77b. And a rack 77 d formed on the lifting rod 76 and engaged with the pinion 77 c.

  When the pedestal 71 of the lifter 70 is at the lower limit position, the upper surface thereof is substantially flush with the upper surface of the body 1. The lower limit position of the pedestal 71 may be higher or lower than the upper surface of the body 1. The position (lift height) of the pedestal 71 is calculated based on the information from the rotary encoder 75 a connected to the motor 75.

  As shown in FIGS. 1 and 2, on the upper surface of the body 1, a pair of laser distance sensors 8 and 8 (position detecting means) are provided separately in the X direction. The laser distance sensor 8 scans in a horizontal direction at a predetermined elevation angle over a predetermined angle range Θ. In addition, this elevation angle is small, and the laser distance sensors 8 and 8 set the caster 102 (leg part) of the cargo 100 mentioned later as a measuring object.

  The cargo R (carrier) shown in FIG. 5 is automatically transported by the robot R configured as described above. Only the bottom 101 of the cargo 100 is shown in FIG. The bottom portion 101 of the cargo 100 has a flat rectangular shape, and casters 102 are attached to the four corners thereof.

  The controller 1a executes the following steps according to the set program. By controlling the pair of crawler devices 2, the robot R is caused to travel from the initial position and dives under the cargo 100. At this time, the receiving table 71 is at the lower limit position as shown in FIG. 4 (A) and FIG.

  Next, the controller 1a detects the position of the robot R relative to the cargo 100. That is, the laser distance sensors 8 are driven to obtain distance information from each of the laser distance sensors 8 to the four castors 102 of the cargo 100. The current position of the robot R with respect to the cargo 100 is calculated based on the distance information of the four casters 102 obtained in this manner. Next, the crawler device 2 is controlled to move the robot R to the reference position. At this reference position, the center of the robot R coincides with the center of the bottom 101 of the cargo 100, and the four sides of the body 1 are parallel to the sides of the bottom 101 of the cargo 100. While calculating the current position of the robot R in real time based on the distance information from the laser distance sensor 8, the crawler device 2 may be controlled so that the current position approaches the reference position.

  Next, the controller 1a controls the four lifters 70, and as shown in FIG. 4 (B) and FIG. As a result, the cargo 100 is lifted and the caster 102 floats from the floor or the ground. Since the load of the cargo 100 is distributed to the four lifters 70, the load on each lifter 70 is reduced and it is not necessary to use the high torque motor 75. Further, the load can be stably lifted and transported by the load distribution load.

  The controller 1a executes lifting control so that the pedestals 71 of the four lifters 70 can bear the load in a more balanced manner. By carrying the load in a well-balanced manner, the cargo 100 can be lifted stably and can be transported stably. Below, various examples of lift control will be described.

Lifting control example 1
The controller 1a controls the motor 75 of the lifter 70 so that the four pedestals 71 select two positions, the lower limit position and the upper limit position. In this control example 1, the upper limit position and the lower limit position of the receiving table 71 may be detected using a limit switch instead of using the information of the rotary encoder 75a of the motor 75.

  The controller 1a drives the four lifters 70 to move the pedestals 71 to the upper limit position, reads the load information from the load cell 78, and the load carried by the four pedestals 71 exceeds the allowable range. It is determined whether there is a bias (specifically, whether the difference between the maximum value and the minimum value exceeds the allowable range). When the determination is negative, that is, when it is determined that the four pedestals 71 bear the load in a well-balanced manner, the lifting control of the cargo 100 ends.

  If there is a large deviation in the load distribution of the load (not shown) loaded on the cargo 100, the four lifters 70 are controlled if the difference in load received by the four pedestals 71 is out of the allowable range. The pedestal 71 is returned to the original lower limit position, and the lifted state of the cargo 100 is released. Next, based on the load information of the four pedestals 71, the correction position of the robot R is calculated. At the correction position, the loads carried by the four pedestals 71 become substantially equal (the load difference falls within the allowable range). Next, by controlling the crawler device 2, the robot R is moved to the corrected position calculated from the current reference position. Next, the lifter 70 is controlled to raise the pedestal 71 and lift the cargo 100 again. In this way, lifting control of the cargo 100 ends.

  In the above control example 1, when the detected load of the four pedestals 71 exceeds the set load at the position where the pedestal 71 is lower than the upper limit position (when the cargo 100 floats from the floor surface) in the same manner as above. The load deviation may be determined.

  If the corrected position calculated above is beyond the liftable range of the cargo 100, or if the difference in load at the four pedestals 71 in the lifted state of the cargo 100 at the corrected position does not fall within the allowable range The controller 1a outputs an abnormality indication signal to stop the conveyance operation.

Lift control example 2
The controller 1a drives the four lifters 70 to raise the pedestal 71, and when the detected load of the four pedestals 71 exceeds the set load based on the load information from the load cell 78 (the cargo 100 is on the floor surface) Whether or not the load carried by the four pedestals 71 is uneven, that is, whether the difference between the maximum value and the minimum value of the load carried by the four pedestals 71 exceeds an allowable range to decide. If the difference in load received by the four pedestals 71 does not exceed the allowable range, lifting control ends.

  When the difference in load carried by the four pedestals 71 exceeds the allowable range, the load at the four pedestals 71 is selected by selecting and lowering only the pedestal 71 which bears the load excessively. Equalize or keep the difference within an acceptable range. In addition, as the pedestal 71 of an overload, for example, the difference with the average value of the loads carried by the four pedestals 71 selects one or a plurality of pedestals 71 that bear the load more than the threshold, and the burden load thereof Determine the amount of descent according to. Alternatively, the pedestal 71 that bears the largest load may be selected and lowered. The selective lowering of the overload receiver 71 may be performed a plurality of times.

  When it is predicted that the load deviation will not fall within the allowable range even when the load bearing 71 of the overload is lowered when determining the load deviation, all the pedestals 71 are lowered to control example 1 Similarly, the position of the robot R is corrected, and lifting control of the cargo 100 by raising the receiving table 71 is performed again.

Lifting control example 3
In Control Example 3, load current detection means for detecting a load current of the motor 75 of the lifter 70 (hereinafter referred to as a lift current) is used as the load detection means, instead of the load cell 78 of the above embodiment. The lift current includes load information of the pedestal 71. Hereinafter, control of the controller 1a based on the lift current will be described with reference to FIG.

  The motors 75 of all the lifters 70 are driven to raise the pedestal 71 (step S1). Next, among the lift currents at the four lifters 70, the difference between the maximum value Imax of the lift current at the lifter 70 with the largest load burden and the minimum value Imin of the lift current at the lifter 70 with the smallest load burden is It is determined whether or not the duration t1 of the state exceeding the allowable range a and further exceeding the allowable range a has reached the predetermined time x (step S2). The duration time t1 starts counting when the load difference exceeds the allowable range a.

If a negative decision in step S2, and resets the duration t1 (step S3), and lift current I is set current value I ₀ or more states in all of the lifter 70, the duration t2 is a predetermined time y It is determined whether it has reached (step S4). When a negative determination is made in step S4, the process returns to step S1.

The above steps S1 to S4 are repeatedly executed until the cargo 100 floats from the floor surface. Negative judgment is in the step S2 (load balance is determined to be good), yet lift I in all of the lifter 70 becomes the current value I ₀ or more, but when an affirmative decision is made in step S4, lifting resets the duration t2 End control.

When an affirmative determination is made in step S2, the duration t1 is reset (step S5), and it is determined whether the number of times of lift N described later has reached the threshold value N ₀ (step S6). If a negative determination is made in step S6, only the overload lifter 70 is selected and lowered for a predetermined time (step S7). This improves the balance of load bearing.
As the lifters 70 for overload, for example, lifters 70 whose lift current difference with the average value of the lift currents of the four lifters 70 is equal to or greater than a threshold value are selected. Alternatively, the lifter 70 with the largest lift current may be selected.

  Next, the lift number N is incremented (step S8), and the process returns to step S1 to raise all the lifters 70 again. If the balance of the load is not improved, an affirmative determination is made again in step S2, and the overload lifter 70 is selected in step S7 and lowered for a predetermined time.

In step S6, when it is determined that the falling number of the lifter 70 of the selected overload has reached the threshold value N _0, the process proceeds to step S9 given up to improve the load balance. In step S9, the pedestals 71 of all the lifters 70 are lowered. The lowering control of the pedestal 71 ends when the four pedestals 71 are engaged with the stopper at the lower limit position and the load current of the motor 75 of the four lifters 70 becomes equal to or more than the set value.

  Further, the process proceeds to step S10, and based on the lift currents of the four lifters 70 when the first affirmative determination is made in step S2, the optimum correction position where the load deviation is within the allowable range and the load can be balancedly balanced. The robot R is moved to the corrected position, and lift control of the cargo 100 is tried again.

  The lowering time of the overload lifter 70 in step S7 may be determined based on the lift current value at the lifter 70 or the difference between the lift current values.

Lifting control example 4
The motor 75 of the lifter 70 uses a motor that performs control by PWM (pulse width modulation). The differences from Control Example 3 shown in FIG. 7 are as follows. In step S1, the duty ratios of the motors 75 of all the pedestals 71 are made equal. In step S7, the duty ratio of the motor 75 of the overload pedestal 71 is selectively reduced for a predetermined time while raising all the pedestals 71. Thereby, the load balance in the four pedestals 71 is improved.

Lift control example 5
In FIG. 7, steps S6 to S8 may be omitted. That is, steps S1 to S4 are executed, and when an affirmative determination is made in step S4, that is, when it is determined that the values of the maximum value and the minimum value of the lift current exceed the allowable range, step S9 is performed, and then step S9. , S10 may be executed.

As described above, after the lifting control of the cargo 100 is completed, the controller 1a controls the crawler device 2 to transport the cargo 100 to a predetermined target position. At this time, since the cargo 100 is lifted with a good load balance, stable transportation can be performed.
After completion of the conveyance, the pedestal 71 is lowered to lower the cargo 100, and the crawler device 2 is controlled to cause the robot R to escape from the cargo 100.

  Since the robot R uses the crawler devices 2 and 2 capable of traveling in two directions as traveling devices, the robot R has good straightness and can easily change the traveling direction without turning on a super soft ground, without damaging the floor or the ground. It's over. In addition, the contact area of the crawler unit 3 is large and it is difficult to slip. Furthermore, since the rolling movement of the robot R is performed by rolling the entire crawler unit 3, the rolling movement is prevented from being stuck by the groove and becoming impossible to move.

  For example, the controller 1a may control the dive into the cargo 100 of the robot R and the transport control of the cargo 100 to the destination by a line trace method. In this case, five optical sensors are provided on the lower surface of the body 1 as shown in FIG. The optical sensor 9 a is disposed at the center of the body 1. The two optical sensors 9x, 9x are arranged equidistantly in the X direction from the center of the body 1. The other two optical sensors 9 y and 9 y are arranged equidistantly in the Y direction from the center of the body 1.

The controller 1a controls the pair of crawler devices 2 and 2 so that the robot R travels along a line provided on the floor surface. For example, when rolling traveling along a line, detection information of the central optical sensor 9a and the left and right optical sensors 9x, 9x is used.
When the central sensor 9a detects a line, and both the left and right sensors 9x and 9x do not detect a line, the controller 1a determines that the robot R is going straight on the line, and goes straight by rolling. continue. When the central sensor 9a detects a line, and also when both the left and right sensors 9x, 9x also detect a line, it is determined that they are going straight on the line, and straight movement by rolling travel is continued. This assumes that the line is thick.

  When the central sensor 9a detects a line, one of the left and right sensors 9x, 9x detects a line, and the other does not detect a line, the controller 1a causes the crawler devices 2 and 2 to crawler in different directions. As a result, after turning the robot R by a predetermined angle and changing its direction, the robot R resumes straight traveling by rolling travel.

More specifically, if the left sensor out of the left and right sensors 9x, 9x detects a line, and the right sensor does not detect a line, then if it is in an advancing state, it turns to the left If you are in a backward situation, turn to the right.
Conversely, if the sensor on the right side out of the left and right sensors 9x and 9x detects a line and the sensor on the left side does not detect a line, then if it is in an advancing state, it turns to the right If you are in a situation where you are retreating, turn to the left.
When a predetermined time, for example, 3 seconds, has passed since the central sensor 9a has not detected the line, it recognizes that the line has deviated and outputs a message.

  In the line tracing method, markings representing positional information are provided on both sides of the line, and when the left and right sensors 9x and 9x detect the markings, the current position is corrected in accordance with the positional information of the markings.

  When traveling straight on the crawler travel, similar control is performed using line detection information of the central sensor 9a and the left and right sensors 9y and 9y.

  In the case of the line tracer method, if the center of the cargo 100 is aligned with the end of the line, the robot R can be positioned at the reference position below the cargo 100 by running the robot R to the end of the line. it can. Instead of the end of the line, the line may be formed with different reflectance portions.

In the automatic travel control and automatic conveyance control of the robot R, when the movement locus is a straight line, the controller 1a is based on the information of the angular velocity sensor provided in the body 1 and the rotary encoders of the motors 51 and 61 of the crawler device 2. Control may be performed.
Briefly explaining, when traveling straight ahead, the angular velocity value from the angular velocity sensor is integrated to calculate the current direction of the robot, and if the difference from the direction before the start of traveling exceeds the set value, the robot Adjust the direction of Specifically, when traveling straight in the crawler traveling mode, the directions of the robot R are corrected by making the speeds of the pair of crawler devices 2 different. When the vehicle travels straight in the rolling travel mode, it is temporarily stopped and the pair of crawler devices 2 and 2 are crawler traveled in different directions to correct the direction of the robot R, and then the rolling travel is resumed.
Further, the controller 1a calculates the traveling distance based on the information from the rotary encoder, and stops the traveling or the conveyance when the traveling distance reaches the set distance. When the vehicle travels straight in the crawler travel mode, the information of the rotary encoder of the motor 51 is used. When the vehicle travels straight in the rolling travel mode, the information of the rotary encoder of the motor 61 is used.

In automatic travel control of the robot R, automatic conveyance control, map matching of the surrounding shape recognized by the laser range sensor or using a GPS sensor to detect the current position and direction, along a preset route You may travel.
In the above embodiment, the traveling of the robot R, the lifting of the cargo 100, and the transportation are all performed automatically by the controller 1a, but remote control may be performed by transmitting a remote control signal from the remote controller to the controller 1a. .

  Next, a second embodiment of the present invention will be described with reference to FIGS. The robot according to the present embodiment has the flat body 1 having a rectangular shape elongated in the X-axis direction as shown in FIG. 9, but the basic configuration is the same as the first embodiment, so It attaches a number and abbreviate | omits the detailed description.

As shown in FIGS. 9 and 10, laser distance sensors 8 are provided at both ends of the body 1 in the X direction. The laser distance sensors 8 have a scanning range of about 240 to 300 ° in the horizontal direction.
The body 1 is provided with four lifters 70 corresponding to the four corners.

  Unlike the first embodiment, the four lifts 70 do not have separate pedestals 71, and their upper ends are connected to a common single receiving plate 80. Specifically, as shown in FIG. 11, the upper end of the rod 76 of each lifter 70 is fixed to the lower surface of the receiving plate 80 via a fixing stand 71 '. The receiving plate 80 is a rectangular flat plate elongated in the X-axis direction as shown in FIG. 9 and is substantially horizontal. In the present embodiment, the dimension of the receiving plate 80 in the X direction is shorter than that of the body 1, and the dimension in the Y direction is substantially equal to that of the body 1.

  As shown in FIG. 10A and FIG. 11, when the four lifters 70 are at the lower limit position, the receiving plate 80 approaches the upper surface of the body 1, and when the four lifters 70 are at the upper limit position, FIG. Leave the top of body 1 as shown in B).

  As in the first embodiment, the cargo 100 (see FIG. 5) is lifted by the four lifters 70 while the robot is under the cargo. In this embodiment, the common receiving plate 80 attached to the four lifters 70 strikes the bottom 101 of the cargo 100 and lifts the cargo 100. Since the receiving plate 80 is wide and flat and substantially horizontal, the bottom portion 101 of the cargo 100 may not be flat and can be stably lifted even if a large number of holes are formed or it is reticulated. it can.

  In this embodiment, as a lift height detection means for detecting the lift height of each lifter 70 (the height of the fixed base 71 'at the upper end), a potentiometer 79 for detecting the rotation of a rotating element of the actuator 73, for example, the worm wheel 77b. Although (shown schematically in FIG. 11) is used, a rotary encoder 75a of the motor 75 may be used.

The lifting control performed by the controller 1a (see FIG. 2) will be described with reference to FIG.
The controller 1 a monitors lift height information of the four lifters 70 and controls the four lifters 70. In order to distinguish the four lifters 70, for example, the upper left lifter 70 is named lifter 1 in FIG. 9, and the lifters 1 are named clockwise lifters 2, 3 and 4 sequentially from the lifter 1. In the lifting control, a first threshold value α and a second threshold value β larger than the first threshold value α are set.

Based on a lift command signal from the remote controller or a signal generated by the controller 1a when the robot reaches the reference position described above, the controller 1a starts lift control. First in step S11, the lift height H1 of the lift 1 determines whether reaches the upper limit height H _U. Immediately after the start of the lift control, a negative determination is made, and the process proceeds to step S12, in which the deviation between the lift height H1 and the minimum value Hmin of the lift heights H1 to H4 of the four lifters 1 to 4 exceeds the second threshold value β Decide whether or not. Immediately after the start of the lift control, a negative determination is made to proceed to step S13, where it is determined whether the deviation (H1-Hmin) exceeds the first threshold value α. Immediately after the start of the lift control, a negative determination is made to proceed to step S14, and the lift control of the lifter 1 is started or continued.

Next, the lifters 2 to 4 are also controlled based on the deviation from the minimum value Hmin based on the lift heights H2, H3 and H4 in the same manner as the lifter 1 (step S20). Immediately after the start of the lift control, the lifters 2 to 4 are also controlled to rise.
After step S20, all of the lift height H1~H4 in step S21 it is determined whether reaches the upper limit value H _U of the lift height. Immediately after the start of the lift control, the determination is negative and the process returns to step S11.

  As the lifts 1 to 4 increase, the lift heights H1 to H4 become different due to the variation of the performance of the motor 75. The lifters 1 to 4 are mutually constrained via the common receiving plate 80, but a difference occurs in the lift heights H1 to H4 due to the play between the components of the lifters 1 to 4 and the distortion of the receiving plate 80 or the like. is there. If the difference between the lift heights H1 to H4 is left as it is, not only the horizontality of the receiving plate 80 is impaired but also the overload of the motor 75 is caused. For example, the lifter with the highest lift height receives a large resistance from the receiving plate 80. The overload of the motor 75 causes a failure and also causes the motor 75 to stop when the overload prevention circuit is provided.

  In the present embodiment, the lifters 1 to 4 are controlled such that the controller 1a corrects the deviation of the lift height in order to avoid the above-mentioned inconvenience. Hereinafter, the lifter 1 will be described in detail. When an affirmative determination is made in step S12, the process proceeds to step S15, and the lifter 1 is temporarily lowered to eliminate a large deviation early. If a negative determination is made in step S13, the process proceeds to step 16 to stop the lifter 1 and wait for the lifter at the minimum lift height to rise. The other lifters 2 to 4 are similarly controlled in step S20.

  As described above, the lift heights H1 to H4 of the lifters 1 to 4 rise while maintaining the substantially equal height so that the deviation falls within the first threshold value α (allowable range). As a result, the receiving plate 80 reliably hits the bottom 101 of the cargo 100 in the horizontal state, and can lift the cargo while maintaining the horizontal state, and the overload of the motors 75 of the lifters 1 to 4 can be avoided.

When the lift height H1 of the lift 1 reaches the upper limit value H _U , an affirmative determination is made in step S11, and the process proceeds to step S17 where the lifter 1 is stopped. The other lifters 2 to 4 are similarly controlled in step S20.
When all the lift heights H1 to H4 reach the upper limit value H _U , an affirmative determination is made in step S21, and the lift control is ended.

In the present embodiment, unloading control is similarly controlled. The controller 1a starts unloading control based on the unloading command signal from the remote controller or a signal emitted when the robot reaches the destination position of the transfer in the controller 1a. Briefly described, first, in step S31, it is determined whether the lift height H1 of the lift 1 has reached the lower limit height _HL . When the determination is negative, the process proceeds to step S32, where it is determined whether the deviation between the lift height H1 and the maximum value Hmax of the four lift heights H1 to H4 exceeds the second threshold value β. If a negative determination is made here, the process proceeds to step S33, where it is determined whether the deviation (Hmax−H1) exceeds the first threshold α. If a negative determination is made here, the process proceeds to step S34, where the lowering control of the lifter 1 is started or continued.

When the result in Step S32 is affirmative, the process proceeds to Step S35, and the lifter 1 is temporarily raised to eliminate a large deviation early. When an affirmative determination is made in step S33, the process proceeds to step 36, the lifter 1 is stopped and the lowering of the lifter at the maximum lift height is awaited.
When the lift height H1 of the lift 1 reaches the lower limit value H _L , an affirmative determination is made in step S31, and the process proceeds to step S37, where the lifter 1 is stopped.
The other lifters 2 to 4 are also controlled in the same manner as the lifter 1 in step S40.
When all the lift heights H1 to H4 reach the lower limit value H _L , an affirmative determination is made in step S41, and the unloading control is ended.

As described above, the receiving plate 80 can be maintained horizontal even in the unloading process, and unloading can be performed while maintaining the bottom portion 101 of the cargo 100 horizontally, and the motor overload of the lifters 1 to 4 is avoided. it can.
The first and second threshold values in the unloading control may be different from the first and second threshold values in the lifting control.

    The lifting and unloading control of the second embodiment can also be applied to the case where the lifts 70 each have a separate pedestal 71 as in the first embodiment. In this case, the bottom portion 101 of the cargo 100 can be stably lifted in a horizontal state.

  The present invention is not limited to the above embodiment, and various forms can be adopted. Three or more lifters may be circumferentially spaced on the body. In this case, for example, the lifters are arranged at intervals in the circumferential direction at the center of the body (more preferably, at equal intervals).

In the case of using a crawler device capable of traveling in two directions, the crawler unit may be configured by a pair of wheels and a belt that is bridged by the wheels and frictionally engaged or pin-engaged with the outer periphery of the wheels.
The grounding structure may not be present. In this case, the angle range occupied by the ground contact member of the crawler portion is made larger than that of the embodiment.
The crawler traveling drive mechanism may be built in the crawler unit.
The crawler unit may be supported in a cantilever manner.
The cargo bed to be transported may be a cart other than the cargo.

  The present invention can be applied to a robot for transporting a loading platform.

1 body 1a controller 2 crawler device (traveling device)
3 Crawler unit 8 Laser distance sensor (position detection means)
20A, 20B crawler 50 drive mechanism for crawler travel (travel drive means)
60 Driving mechanism for rolling travel (traveling driving means)
70 lifter 71 pedestal 73 actuator 75a rotary encoder (lift height detection means)
78 Load cell (load detection means)
79 Potentiometer (lift height detection means)
80 Receiving Plate 100 Cargo
L1 First axis of rotation L2, L2 'Second axis of rotation R Robot

Claims (15)

A robot that transports a loading platform,
The body,
A traveling device provided in the body;
3 or more lifters provided on the above-mentioned body and lifting the above-mentioned loading platform,
A controller provided in the body and controlling the traveling device and the lifter;
A robot for transporting a loading platform characterized by comprising:   The robot for transporting a loading platform according to claim 1, wherein the body has a flat rectangular shape, and the lifters are provided at four corners corresponding to the four corners of the body.   The robot for transporting a load carrier according to claim 1 or 2, wherein each of the lifters has an independent support for receiving a load from the support and an actuator for moving the support up and down. Each of the three or more lifters includes load detection means for detecting the load received by the pedestal from the bed.
In the state where the controller lifts the bed by the three or more lifters, the pedestal of the three or more lifters is based on load information from the load detection means of the three or more lifters. The load carrier robot according to claim 3, wherein the load deviation is detected.   The robot for transporting a loading platform according to claim 4, wherein the load detection means is a load cell incorporated below the pedestal.   5. The robot according to claim 4, wherein said load detection means is a load current detection means for detecting a load current of said actuator in the process of lifting said loading platform. The body is provided with position detection means for detecting the relative position of the body with respect to the loading platform,
The controller lowers the pedestal by controlling the three or more lifters when it is determined that the load received by the pedestals of the plurality of three or more lifters exceeds the allowable range. Move the body to a correction position where the load deviation falls within the allowable range by controlling the traveling device based on the load information and the position information from the position detection means. The robot for transporting a loading platform according to any one of claims 4 to 6, characterized in that the loading platform is lifted again by controlling the plurality of three or more lifters after the body has reached the correction position. .   When the controller determines that the load deviation received by the pedestals of the three or more lifters exceeds the allowable range, the controller cancels the load deviation or falls within the allowable range. The robot for transporting a loading platform according to any one of claims 4 to 6, wherein the lifter is selectively controlled.   The controller calculates the difference between the maximum value and the minimum value of the load carried by the pedestals of the three or more lifters as the deviation of the load, and the difference between the maximum value and the minimum value exceeds the allowable range 9. The robot according to claim 8, wherein the lifter corresponding to the pedestal is selectively controlled to lower the pedestal bearing at least the maximum load when judged. The actuator of the lifter is PWM controlled,
The controller calculates the difference between the maximum value and the minimum value of the load carried by the pedestals of the three or more lifters as the deviation of the load, and the difference between the maximum value and the minimum value exceeds the allowable range 9. The robot according to claim 8, wherein the duty ratio of the actuator corresponding to the pedestal carrying at least the maximum load is set lower than the duty ratio corresponding to the other pedestals.   3. The three or more lifters are connected at their upper ends to one flat common receiving plate, and lift the cargo bed via the receiving plate. Carrier transport robot.   The three or more lifters each have lift height detection means, and when the controller lifts the bed, the three or more lifters are based on lift height information from the lift height detection means. The robot for transporting a loading platform according to claim 3 or 11, characterized in that the lifter is controlled such that the lift height deviation of the lifter falls within an allowable range.   The controller monitors the lift height of each of the three or more lifters, and the deviation between the lift height of the monitored lifter and the minimum value of the lift heights of the three or more lifters is greater than a first threshold The load carrier robot according to claim 12, wherein the robot is stopped in a certain case and stands by until the deviation falls within a first threshold.   The controller sets a second threshold larger than the first threshold, and the deviation between the lift height of the lifter to be monitored and the minimum lift height of the three or more lifters is larger than the second threshold. The robot for transporting a loading platform according to claim 13, wherein the lifter to be monitored is lowered until the deviation falls within a second threshold. The traveling device includes a pair of crawler devices extending in a first direction and spaced apart from each other in a second direction orthogonal to the first direction,
Each of the pair of crawler devices has a crawler unit rotatably supported by the body so as to be rotatable about a first rotation axis extending in the first direction, each crawler unit being along the first rotation axis And a pair of crawler portions provided on the support and disposed across the first rotation axis,
Furthermore, each of the crawler devices has a rolling traveling drive mechanism for rotating the crawler unit around the first rotation axis, and a crawler traveling drive mechanism for simultaneously driving the pair of crawler portions. The robot for transporting a loading platform according to any one of claims 1 to 14.

Images