JP4220852B2 - Transfer crane - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transfer crane that is used as a cargo handling facility such as a container in a yard such as a harbor and travels on a yard with wheels such as rubber tires according to a guideline. Related to transfer crane.
[0002]
[Prior art]
The transfer crane is supported by the girder so that it can run along the girder, a gate-shaped airframe consisting of a leg on both sides and a girder that connects the upper part of the leg, a tire driven by a motor at each of the lower ends of both legs. And a hanging tool suspended from the trolley via a wire that can be wound and unwound. In the yard, the guideline, which is the traveling target line of the transfer crane (hereinafter referred to as “crane”), is laid.
[0003]
The crane is provided with a detector for detecting deviation from the guideline for automatic traveling, and the deviation amount and deviation angle from the guideline are calculated based on the detection value of the detector, and the deviation amount and deviation angle are calculated. In order to make it smaller, the speed of the tires on both legs is controlled, and the crane is moved along the guideline.
[0004]
Since the crane is only planned to travel straight in normal travel and not planned to bend significantly, there is no mechanism to change the travel direction by turning the axle of the tire while traveling. The tires are fixedly arranged so that their axles are parallel to each other. And the speed of the tire of a right-and-left leg is controlled separately, and the running direction is changed by adjusting the speed difference of a right-and-left tire. The tire axle is also parallel to the girder.
[0005]
On the road surface where the crane runs, a rain gradient is provided so that rainwater flows out without accumulating, and this rain gradient is generally an inclined surface with a height difference in a direction substantially perpendicular to the guideline. Yes. Therefore, when the crane is traveling on a road surface having such a rain gradient, the crane tends to deviate from the guideline due to gravity below the inclined surface of the rain gradient.
[0006]
In the conventional automatic traveling control of the crane described above, the speeds of the left and right tires are controlled based on the amount and angle of deviation of the crane. The vehicle would run in a direction inclined to the upper side of the inclined surface, and the deviation angle could not be reduced by the time of stopping.
[0007]
By the way, a large number of rectangular parallelepiped containers are arranged in an orderly manner in such a position that their bottom sides are parallel or perpendicular to the guideline. Therefore, when the transfer crane stops, the line where the trolley travels along the girder and the line where the container is lined will not be parallel unless the deviation angle is zero with respect to the guideline. The container could not be hung at the correct position or the container at the proper position could not be lifted, and the crane had to be run again to correct the stop position, resulting in poor work efficiency.
[0008]
Conventionally, as a means of improving this, in a crane traveling with feedback control of the difference in speed between the left and right tires so that the deviation amount and deviation angle are reduced, the deviation angle is made smaller than the deviation amount immediately before stopping. It was thought that the main control was. Such a device can reduce the shift angle at the time of stoppage, compared to the control for reducing both the shift amount and the shift angle, regardless of whether it is immediately before the stop (see, for example, Patent Document 1).
[0009]
[Patent Document 1]
JP 2002-20076 (paragraph 0028 to paragraph 0033)
[0010]
[Problems to be solved by the invention]
However, since such a thing always stops in a transient state of feedback control, the deviation angle may not be sufficiently reduced by the time of stopping depending on the speed and deviation angle conditions immediately before the stop. In such a case, after the stop, it is necessary for the driver to correct the crane posture by manual operation, and the conventional problems have not been sufficiently solved.
[0011]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a crane capable of reliably stopping the crane at an appropriate position and improving traveling control accuracy. And
[0012]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following means.
According to the first aspect of the present invention, the left and right legs, a connecting portion that connects the two legs, a suspension that travels along the connecting portion and suspends a load, and the left and right legs are provided independently. Left and right traveling in a transfer crane comprising a traveling wheel that can be adjusted in speed and a control device that controls the speed of the left and right traveling wheels so that a deviation angle between a traveling direction line and a traveling target line is reduced. A deceleration setting unit that sets the negative acceleration of each wheel, and a stop control unit that decelerates the left and right traveling wheels based on the setting of the deceleration setting unit when the condition is determined to be immediately before stopping. It is characterized by having prepared.
[0013]
With this configuration, when it is determined that the vehicle is immediately before the stop, it is possible to set the appropriate negative acceleration for each of the left and right traveling wheels, and based on that, the left and right traveling wheels can be decelerated. It can be stopped with a small deviation angle with high accuracy. As the appropriate negative acceleration of the left and right traveling wheels, for example, a negative acceleration value selected by a person based on experience may be input, and the deceleration setting unit may set the negative acceleration. When moving between predetermined locations in a predetermined yard, it is possible to know the appropriate negative acceleration based on tests and experience, so the state where the deviation angle is zero with high accuracy by such simple means Can be stopped. When there are many moving parts, negative acceleration data based on a test or the like may be stored in a memory as a table, and the negative acceleration may be set with reference to this data.
[0014]
The “traveling direction line” is a line that is perpendicular to the axle of the traveling wheel in the horizontal plane. The “deviation angle” refers to an angle formed by a traveling direction line with respect to a predetermined traveling target line as a reference line. In a state where the traveling wheel is traveling in parallel with the traveling target line, the deviation angle is zero. Here, zero or parallel is not a strict rule, but a rule within a practical range that does not affect the cargo handling operation.
[0015]
The invention according to claim 2 is the transfer crane according to claim 1, wherein the deceleration setting unit is from a position state when the condition is determined to be just before the stop to a position state where the deviation angle becomes zero, A first calculation unit that calculates the amount of travel of the traveling wheel required to advance only the delayed traveling wheel of the left and right traveling wheels, and a condition when it is determined that the left and right traveling wheels are immediately before stopping A second calculator for calculating the amount of movement of each of the left and right traveling wheels when decelerating at a negative acceleration of a rated fixed value until the speed becomes zero, and the left and right traveling wheels calculated by the second calculation unit A third calculation unit for calculating a difference between the movement amounts of the first calculation unit, a fourth calculation unit for calculating a difference between the movement amount calculated by the first calculation unit and the movement amount difference calculated by the third calculation unit, 2 The left and right movement amounts calculated by the calculation unit and the fourth calculation A fifth calculation unit for calculating a time until stopping by multiplying the total moving amount calculated by the difference of the moving amount calculated in step 2 and dividing the value by one of the left and right speeds when it is determined to be immediately before stopping; When a condition that is determined to be immediately before stopping is obtained, including a sixth calculation unit that calculates the negative acceleration by dividing the speed of one of the left and right when it is determined immediately before by the time calculated by the fifth calculation unit, The negative acceleration calculated by the sixth calculator is set on one of the left and right traveling wheels, and the negative acceleration of the rated fixed value is set on the other traveling wheel.
[0016]
With this configuration, appropriate negative acceleration is automatically calculated and set according to the deviation angle and traveling speed when it is determined that the vehicle is just before stopping, and stop control is performed based on it. The angle can be zero. In addition, zero here is zero in the range which does not have trouble in cargo handling work, and is not numerically exact zero.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the transfer crane (hereinafter referred to as “crane”) 1 is referred to as front, rear, left, and right (directions of F, A, L, and R described in FIG. 1).
[0018]
In addition, since this crane 1 can drive | work back and forth, this front and back and right and left are for convenience of explanation. Also, the nickname for this direction is different from the nickname among those skilled in the art. That is, in those skilled in the art, since a person who operates the crane 1 conventionally calls a direction in a posture toward the hanging tool, the front and rear of the crane 1 in this specification are referred to as the left and right. The left and right sides of 1 are called front and rear.
[0019]
<Transfer crane>
The structure of the crane 1 is the same as the conventional one as shown in FIG. The main structures are the connecting structures 10 and 20 which are parallel to each other with a predetermined distance in the front and rear. The connecting structures 10 and 20 have leg portions 11, 12, 21, and 22 that extend vertically apart from left and right, and horizontal portions 13 and 23 that connect the upper portions of the left and right leg portions 11, 12, 21, and 22. It has a gate shape. The horizontal portions 13 and 23 are girder (corresponding to “connecting portion” in the claims).
[0020]
In the leg portions 11, 12, 21, and 22, the lower connection portions 15 and 25 that connect the lower ends of the front and rear legs 11, 12, 21, and 22 and the upper connection portions 14 and 24 that connect the upper portions of the leg portions, respectively. Is fixed. The upper and lower connecting portions 15, 25, 14, 24 extend in a direction orthogonal to the connecting structures 10, 20.
[0021]
There are a pair of front and rear traveling platforms 16, 17, 26, and 27 supported below the left and right lower connection portions 15 and 25, respectively, and tires 31 that are integrated with the front and rear are respectively mounted on the traveling platforms 16, 17, 26, and 27. 32, 33, 34, 35, 36, 37, 38 (corresponding to “traveling wheels” in the claims) are provided.
[0022]
The left and right tires 31 to 38 can be driven by a traveling motor (not shown) so that the left and right tires can be independently adjusted in speed. The axles of all the tires 31 to 38 are parallel or collinear with each other. The axles of the tires 31 to 38 cannot be turned around the vertical axis except in a special case where the traveling lane is changed.
[0023]
Moreover, the line of the length direction of the girders 13 and 23 used as the running direction of the trolley 41, and the line of the axle of the tires 31-38 are parallel. A line perpendicular to the axles of the tires 31 to 38 in the horizontal plane is a traveling direction line of the crane.
[0024]
Further, a trolley 41 is stretched over the girders 13 and 23 of the front and rear connecting structures 10 and 20, and the trolley 41 is supported movably along the longitudinal direction of the connecting structures 10 and 20. Can be moved. A hanging tool 42 is suspended from the trolley 41 via a wire so as to be wound up and down. The hanger 42 can hold the container detachably. By the movement of the crane 1 and the trolley 41, the hanging tool 42 is moved to the container loading position and the container is loaded. In addition, since the trolley 41 travels along the girders 13 and 23, the hanging tool 42 travels along the girders 13 and 23.
[0025]
Guide lines 45 (corresponding to “travel target line” in the claims) are provided on the ground. The crane is scheduled to travel along these guidelines 45. Therefore, in an ideal traveling state or a stopped state for cargo handling, the guide line 45 is orthogonal to the longitudinal line of the girders 13 and 23 as the traveling direction of the trolley 41 and the axle line of the tires 31 to 38 in the horizontal plane. The positional relationship is
[0026]
<Slip detector>
In the front and rear traveling platforms, there is a member extending downward to support the tire shaft. The base end portions of the protruding members 28 and 29 extending further outward from the side surface of the member are fixed to the member. Deviation detectors 43 and 44 for detecting deviation from the guideline 22 are attached to the tip portions of the overhang members 23 and 24, respectively.
[0027]
The deviation detectors 43 and 44 are preferably one of the following three types.
The displacement detector recognizes the image with the camera sensor, and the video signal of the guideline recognized by the front and rear cameras while driving is detected as the displacement from the guideline by the image processing device, and the correlation processing is performed to recognize the displacement amount. . As a guideline in this case, a white background paint applied along the ground traveling road surface and a black line paint having a width of about 20 mm is used.
[0028]
The deviation detector is a sensor for detecting the intensity of the electromagnetic field, and the deviation amount from the guideline is recognized from the front and rear detection sensors. In this case, as a guideline, a cable that generates an electromagnetic field around by passing a low-frequency current is used by being embedded in a groove along a traveling path having a depth of about 20 mm from the ground surface.
[0029]
The deviation detector is a magnetic sensor, and the deviation amount is recognized from the position of the guideline detected by the front and rear magnetic sensors. In this case, as a guideline, a plate-like rubber magnet having a width of about 10 mm is used by being embedded in a groove along a traveling path having a depth of 30 mm from the ground surface.
[0030]
<Shift angle, shift amount>
As a value indicating how much the crane 1 is traveling with respect to the guideline 45, there are a “deviation amount” and a “deviation angle” that have been conventionally used. This calculation method will be described.
[0031]
As shown in FIG. 2, when the crane is viewed in plan, the rectangle formed by the legs, the girders 13 and 23, the lower connection parts 15 and 25, and the upper connection part is recognized as a simplified form of the crane, and the guideline 45 The distance from two vertices close to the guideline 45 is y1, and y2 is the shift length to the front and back guideline 45. The deviation lengths y1 and y2 are calculated based on the deviation values x1 and x2 detected by the deviation detectors 43 and 44, the shape of the deviation detectors 43 and 44, and the shape, positional relationship, and size of the crane.
[0032]
The average value of the shift lengths y1 and y2 is referred to as “shift amount” e. This “deviation amount” is calculated by the equation e = (y1 + y2) / 2.
[0033]
The “deviation angle” refers to an angle formed by the guide line 45 as a reference line and a travel direction line with respect to this line. The “traveling direction line” is a line that is perpendicular to the axle of the traveling wheels 31 to 38 in the horizontal plane. This “deviation angle” is calculated by the equation θ = (y1−y2) / 2. In a state where the traveling wheels 31 to 38 are traveling in parallel with the guideline 45, the deviation angle is zero. The traveling of the crane 1 is ideally in a state where these two values are zero.
[0034]
<Control configuration>
In the crane 1 configured as described above, as shown in FIG. 3, a notch 51 operated by an operator is connected to the traveling track control device 52, and a target speed command value VN corresponding to the operation of the notch 51 is provided. Is input to the traveling track control device 52. The traveling track control device 52 is connected so that signals of the deviation detectors 43 and 44 can be inputted, and deviation values x1 and x2 with respect to the guideline 45 detected by the deviation detectors 43 and 44 are inputted.
[0035]
In the traveling track control device 52 of the crane 1 configured as described above, the deviation amount e and the deviation angle θ of the crane 1 are obtained based on the deviation values x1 and x2 from the guideline 45 detected by the deviation detectors 43 and 44, The left and right speed command values VL and VR are calculated so that the deviation amount e and the deviation angle θ are eliminated.
[0036]
The command values VL and VR are input to the traveling speed control devices 53 and 54 corresponding to the left and right respectively. The traveling speed control devices 53 and 54 drive and control the rotational speeds of the traveling motors 55 and 56, that is, the traveling speed of the tire, based on the speed command values VL and VR.
[0037]
The traveling motors 55 and 56 are provided with rotational speed detectors 57 and 58 for detecting the rotational speed of the motor, and the detected values are returned to the traveling speed control devices 53 and 54 for feedback control. Further, the detected value is also input to the traveling track control device 52, converted into a tire traveling speed, and used for calculation.
[0038]
The travel activation control device 52 and the travel speed control devices 53 and 54 constitute a control device that controls the speeds of the left and right tires so that the deviation angle between the travel direction line and the guideline becomes small.
[0039]
<Driving control>
The driver travels by issuing a target speed command value VN as a command by operating the notch 51. The vehicle accelerates until the target speed corresponding to the notch 51 is reached, and then travels at a constant speed. When the driver cuts the notch 51, the driver starts deceleration and stops traveling. The notch 51 has a predetermined number, for example, six stages, and an initial speed corresponding to the notch 51 is determined.
[0040]
When the notch 51 is changed, the acceleration or deceleration is performed until the target speed of the corresponding notch 51 is reached at the rated acceleration or deceleration. In addition to this basic operation control, control for reducing deviation from the guideline 45 is added. First, a description will be given of the control for reducing the deviation at the time of traveling that does not result in stopping.
[0041]
As the initial speed command value corresponding to the target speed command value VN, the speed command values VL and VR of the traveling motors 55 and 56 are set to VN0. When the crane travels with a certain inclination (deviation angle θ) with respect to the guideline 45 due to the inclination of the road surface or the like, the deviation detectors 43 and 44 detect the deviation amount e and deviation based on the deviation values x1 and x2. Using the angle θ, the operation amount (correction amount) Δv for the speed command values VL and VR of the traveling motors 55 and 56 can be obtained by the equation Δv = a × e + b × θ + c × ｃedt + d × ｄθdt. t is time, and the integration is from 0 to t with respect to time t.
[0042]
In this case, a, b, c, and d are coefficients for converting the shift amount e or the shift angle θ into the speed difference between the left and right traveling motors 55 and 56, and are calculated in advance by simulation, or an actual machine. It was adjusted and set so as to be more stable by the test.
[0043]
Then, the speed command values VL and VR of the traveling motors 55 and 56 are corrected as shown in the expressions VL = VN0 + Δv / 2 and VR = VN0−Δv / 2.
Such control is auto-steering control conventionally performed. Also in the present embodiment, the vehicle travels based on this conventional control until the condition determined to be immediately before the stop is reached.
[0044]
<Flow chart, travel mode>
Referring to the flowchart, as shown in FIG. 4, first, in step S <b> 1, the operator operates the notch 51 to input the target speed command value VN to the traveling track control device 52. The initial command value VN0 is output as speed command values VL and VR to the travel speed control devices 53 and 54 to control the speed of the travel motors 55 and 56.
[0045]
Next, in step S2, deviation values x1 and x2 with respect to the guideline 45 are obtained by the deviation detectors 43 and 44. In step S3, displacement lengths y1 and y2 are calculated based on the displacement values x1 and x2 and the crane shape. In step S4, a deviation amount e and a deviation angle θ are obtained.
[0046]
In step S5, it is determined whether or not the conditions determined to be immediately before the stop are met. If the condition is immediately before the stop, the process proceeds to 1 in step S9, and the stop mode is set. Otherwise, the process proceeds to step S6. Then, the travel mode is set. Here, as conditions for determining immediately before the stop, the notch operation is zero notch and the traveling speeds of the left and right tires (converted from the detection values of the rotational speed detectors 57 and 58) are equal to or less than a predetermined value, for example, 0.7 m / The conditions below s are adopted.
[0047]
As shown in FIG. 5, in step S6, an operation amount (correction amount) Δv for the speed command values VL and VR is obtained. In step S7, the speed command values VL and VR of the respective traveling motors 17 and 18 are obtained based on the operation amount Δv. In step S8, the travel speed control devices 33 and 34 travel using the speed command values VL and VR. The speed of the motors 55 and 56 is controlled. Next, the process returns to step S1.
[0048]
By the way, the road surface on which the crane 1 travels is provided with a rain gradient that has a height difference in the left-right direction substantially perpendicular to the traveling direction of the crane 1 so that rainwater or the like flows without collecting. Therefore, as described above, when the speed command values VL and VR of the traveling motors 55 and 56 are corrected with the operation amount Δv based on the displacement amount e and the displacement angle θ, the crane travels on the road surface having this rain gradient. At this time, the crane 1 travels in a posture inclined to the high side of the inclined surface with respect to the guideline 45, that is, in a state where the deviation angle θ is positive, and stops in this inclined posture.
[0049]
Then, the trolley 19 cannot be moved in the direction orthogonal to the guideline 45, and the hanging load and lifting accuracy of the suspended load are lowered. In order not to stop in such a state, stop control described below is performed.
[0050]
<Stop control>
An outline of the control when the stop mode is entered will be described. Decrease one of the left and right tires at a fixed rated deceleration (negative acceleration), set the other tire on the left and right to be smaller than the rated deceleration, and move longer than the rated deceleration. Thus, the running speed of both the left and right tires is zero, that is, the deviation angle is controlled to be zero when the tire stops.
[0051]
This will be described in detail. The left travel speed VL0 and the right travel speed VR0 when the conditions immediately before the stop are obtained are obtained. Here, as the traveling speed, the traveling speed obtained by converting into the rotation of the tire based on the value detected from the rotational speed detectors 57 and 58 of the motor is used. This detected value is input to the traveling track control device 52, and the control device 52 performs a calculation described here based on this value.
[0052]
The travel travel amounts SL and SR until the left tires 31 to 34 and the right tires 35 to 38 stop when the travel speeds VL0 and VR0 are decelerated at the rated deceleration a0 are calculated. The calculation formula is SL = (VL0 × VL0) / (2 × a0), SR = (VR0 × VR0) / (2 × a0), and the difference between these two travel amounts is ΔS1 = SL−SR. When the left side travel speed is faster than the right side travel speed, the left tires 31 to 34 have a larger travel travel amount SL, and therefore ΔS1 has a positive value. Conversely, when the right travel speed is slower than the left travel speed, ΔS1 is a negative value.
[0053]
Next, the movement amount ΔS2 required to advance only the delayed tires 31 to 34 of the left and right tires 31 to 38 from the position state at the time immediately before stopping to the position state where the deviation angle becomes zero. Ask for. It is considered that the crane 1 is in a position as shown in FIG. In this case, in order for the main shafts of the left and right tires 31 to 38 to be positioned at right angles to the guideline 45, it is necessary to advance the left side by ΔS2 relative to the right side. When the distance between the front and rear legs is L1, and the distance between the left and right legs is L2, ΔS2 = L2 × (y1−y2) / L1.
[0054]
In short, ΔS1 is the difference in travel distance between the left and right tires 31 to 38 when the vehicle decelerates at the rated deceleration a0 and stops, and ΔS2 sets the deviation angle θ to zero from the position state in the condition immediately before stopping. This is the minimum travel amount of the left and right tires 31 to 38 required for the purpose. Therefore, the difference between ΔS1 and ΔS2 is such that when the crane 1 is stopped at a right angle with respect to the guideline 45 (the deviation angle θ is zero), the left and right tires 31 are required more than when the rated deceleration a0 is stopped. The travel distance difference is -38.
[0055]
Depending on the magnitude of these two travel distances, it is necessary to advance the left tires 31 to 34 further than the deceleration traveling at the rated deceleration, and the right tires 35 to 38 are further advanced than the deceleration traveling at the rated deceleration. Separate cases when necessary.
[0056]
In order to stop at a deviation angle θ of zero, if ΔS2 is larger than ΔS1, it is necessary to further advance the left side by ΔS = ΔS2−ΔS1. The right deceleration aR remains the rated deceleration a0. Next, a left deceleration aL at which the left tires 31 to 34 stop at a position that matches the stop position of the right tires 35 to 38 is obtained.
[0057]
Since the left tires 31 to 34 need to be further advanced by ΔS before stopping, the movement amount of the left tires 31 to 34 until stopping is (SL + ΔS). The time required for the left tires 31 to 34 to decelerate from the speed VL0 at a constant deceleration (negative acceleration) and stop running is obtained from the equation t = 2 × (SL + ΔS) / VL0, and then this time t is used. Thus, the left side deceleration at this time is obtained from the equation aL = VL0 / t.
[0058]
The difference in deceleration between the left side and the right side is Δα = a0−aL. Then, the left deceleration aL is smaller than the right deceleration aR, and the movement amount of the left tires 31 to 34 until the travel stop is increased by ΔS than when the rated deceleration a0, and the tires 31 to 38 are stopped when the travel is stopped. The axle direction and the longitudinal direction of the girders 13 and 23 can be stopped at a position perpendicular to the guideline 45.
[0059]
If ΔS2 is smaller than ΔS1, the right side needs to be further advanced by ΔS = ΔS1−ΔS2. The left deceleration aL remains the rated deceleration a0. Next, the right deceleration aR at which the right tires 35 to 38 are stopped at the position corresponding to the stop of the left tires 31 to 34 is obtained.
[0060]
Since the right tires 35 to 38 need to be further advanced by ΔS before stopping, the amount of movement of the right tires 35 to 38 until stopping is (SR + ΔS). The time required for the right tires 35 to 38 to decelerate from the speed VR0 at a constant deceleration (negative acceleration) and stop running is obtained from the equation t = 2 × (SR + ΔS) / VR0, and then the time t is calculated. The right side deceleration aR at this time is obtained from the formula aR = VR0 / t.
[0061]
The difference in deceleration between the left side and the right side is Δα = a0−aR. Then, the right deceleration aR is smaller than the left deceleration aL, and the amount of movement of the right tires 35 to 38 until the stop of travel is increased by ΔS compared to the case of the rated deceleration a0. The axle direction and the longitudinal direction of the girders 13 and 23 can be stopped at a position perpendicular to the guideline 45.
[0062]
In any case of ΔS2 and ΔS1, the right travel speed VR is VR0−aR × T, and the left travel speed VL is VL0−aL × T. Here, T is an elapsed time since reaching the stop mode.
[0063]
<Flowchart, stop mode>
This will be described with reference to the flowchart of FIG.
If it is determined in step S5 that the stop mode is set, the process proceeds to 1 in step S9.
In 1 of step S9, the left and right traveling travel SL and SR when the vehicle is decelerated at the rated deceleration a0 are calculated.
[0064]
Next, in step S9-2, the left and right traveling movement difference ΔS1 when the vehicle is decelerated at the rated deceleration a0 is calculated. Next, in step S10, only the delayed traveling wheel of the left and right traveling wheels is advanced from the position state at the time when the condition is determined to be just before the stop to the position state where the deviation angle becomes zero. A necessary travel movement amount ΔS2 is calculated.
[0065]
Next, in step S11, the magnitude of ΔS1 and ΔS2 is determined. If ΔS2 is greater than or equal to ΔS1, that is, if it is necessary to further increase the left travel distance before stopping, the process proceeds to step S12. Since the magnitude relationship between ΔS1 and ΔS2 is often almost constant depending on the yard or crane, the determination in step S11 may be omitted.
[0066]
In step S12, the required movement amount ΔS is calculated more than when the vehicle is decelerated with the rated deceleration. Next, in step S13, a time t required when the travel distance required for the left tire is decelerated at a constant deceleration is calculated.
Next, in step S14, the deceleration aL of the left tire is calculated, and the deceleration aR of the right tire is set to the rated deceleration a0.
[0067]
Next, in step S18, a right travel speed command value VR and a left travel speed command value VL value at the previously calculated deceleration are calculated.
Next, in step S19, the traveling motor is decelerated based on the previously calculated left and right traveling speed command values.
[0068]
Next, in step S20, it is determined whether the left and right traveling speeds have become zero, and steps S18 and S19 are continued until zero. When either the left or right traveling speed becomes zero, the tire on the zero side stops and only the tire on the non-zero side is subjected to deceleration control.
[0069]
On the other hand, if ΔS2 is smaller than ΔS1 in step S11, that is, if the amount of travel on the right side needs to be larger, the process proceeds to step S15. Next, in step S15, the required movement amount ΔS is calculated more than when the vehicle is decelerated while maintaining the rated deceleration. Next, in step S16, a time t required when the traveling amount necessary for the right tire is decelerated at a constant deceleration is calculated.
[0070]
Next, in step S17, the deceleration aR of the right tire is calculated, and the deceleration aL of the left tire is set to the rated deceleration a0. Next, the process proceeds to step S18, and the same processing as described above is performed.
[0071]
The traveling track control device 52 performs the processes of steps S8 to S18 and S20. Deceleration that sets the deceleration (negative acceleration) of each of the left and right traveling wheels so that the deviation angle becomes zero at the time of stopping when the part having the function to perform this processing becomes a condition determined to be immediately before stopping Corresponds to the setting unit. The travel speed control devices 53 and 54 perform step S19. The part having the function of performing this process corresponds to a stop control unit that decelerates the left and right wheels based on the setting of the deceleration setting unit.
[0072]
Also, step S10 is the first calculation unit, step S9 1 is the second calculation unit, step S9 1 is the third calculation unit, step S12 and step S15 are the fourth calculation unit, step S13 and step S16. Corresponds to the fifth calculator, and part of steps S14 and S17 corresponds to the sixth calculator.
[0073]
As an appropriate deceleration (negative acceleration) of the left and right traveling wheels, in addition to the above example, a value selected by a person based on experience is input, and that value is set as a negative acceleration by the deceleration setting unit You may do it. The movement of the transfer crane is often in a relatively limited range. When only moving between predetermined places in a predetermined yard, an appropriate negative acceleration can be known based on tests and experiences. Therefore, even such simple means can be stopped in a state where the deviation angle becomes zero with high accuracy.
[0074]
In addition, when there are many moving locations, appropriate negative acceleration data based on tests etc. is stored in the memory of a control device such as a computer, and the control device selects the negative acceleration from this data according to the moving location, The value may be set as a negative acceleration by the deceleration setting unit.
[0075]
By performing the stop control in this manner, since the longitudinal direction of the girder is orthogonal to the guideline 45 in a state where the crane is stopped, the hanging tool 42 suspended from the trolley 41 is arranged like a matrix of containers. It can be moved to a position along the array. Since it is not necessary to finely adjust the crane position by restarting the crane after stopping the crane, the cargo handling operation can be performed quickly.
[0076]
【The invention's effect】
According to the present invention, when the traveling is stopped, the angle of deviation can be made substantially zero, so that the connecting portion along which the hanging tool travels can be positioned at a right angle with respect to the traveling target line, and the crane is aligned again after stopping. This makes it possible to immediately start the cargo handling work, thereby reducing the driver's work time and reducing the burden.
[Brief description of the drawings]
FIG. 1 is a perspective view of a conventional crane and a crane according to the present embodiment.
FIG. 2 is a plan view in which simplified forms of the crane according to the present embodiment are stacked.
FIG. 3 is a block diagram of control.
FIG. 4 is a flowchart.
FIG. 5 is a flowchart.
FIG. 6 is a flowchart.
[Explanation of symbols]
1 ... Transfer crane
10 ... Connection structure
11 ... Leg
12 ... Leg
13 ... Horizontal part, girder
14 ... Upper connection part
15 ... Lower connection part
16 ... Travel platform
17 ... Travel platform
20 ... Connection structure
21 ... Leg
22 ... Leg
23. Horizontal part, girder
24. Upper connection part
25. Lower connection part
26 ... traveling platform
27 ... Travel platform
28 ... Overhang member
29 ... Overhang member
31 ... tyre
32 ... tyre
33 ... tyre
34 ... tyre
35 ... tyre
36 ... tyre
37 ... tyre
38 ... tyres
41 ... Trolley
42 ... Hanger
43 ... Misalignment detector
44. Deviation detector
45 ... Guidelines
51 ... Notch
52 ... Traveling track control device
53. Travel speed control device
54 ... Traveling speed control device
55 ... Motor for traveling
56. Motor for traveling
57 ... Rotation speed detector
58 ... Rotation speed detector

Claims (1)

Left and right legs, a connecting part that connects the two legs, a hanging tool that runs along the connecting part and hangs a load, and a traveling wheel that is provided on each of the left and right legs and that can be independently speed-adjusted on each of the left and right. In a transfer crane comprising a control device for controlling the speed of the left and right traveling wheels so that the deviation angle between the traveling direction line and the traveling target line is reduced,
A deceleration setting unit that sets the negative acceleration of each of the left and right traveling wheels, and a stop control that decelerates the left and right traveling wheels based on the setting of the deceleration setting unit when the condition is determined to be immediately before stopping. and a part,
The deceleration setting unit advances only the delayed traveling wheel of the left and right traveling wheels from the position state when the condition is determined to be immediately before the stop to the position state where the deviation angle becomes zero. A first calculation unit for calculating a travel amount of the traveling wheel required;
Calculate the amount of movement of the left and right traveling wheels when decelerating with negative acceleration of the rated fixed value until the speed becomes zero from the speed when the right and left traveling wheels are determined to be immediately before stopping. 2 calculation units;
A third calculation unit for calculating a difference between the movement amounts of the left and right traveling wheels calculated by the second calculation unit;
A fourth calculation unit that calculates a difference between the movement amount calculated by the first calculation unit and the movement amount difference calculated by the third calculation unit;
The left and right speeds when the moving amount obtained by summing the moving amount calculated by the second calculating unit and the moving amount difference calculated by the fourth calculating unit is further doubled and the value is determined to be immediately before stopping. A fifth calculator for calculating the time until stopping by dividing by,
A sixth calculation unit that calculates a negative acceleration by dividing one of the left and right speeds when it is determined immediately before the stop by the time calculated by the fifth calculation unit;
When the condition is determined to be immediately before stopping, the negative acceleration calculated by the sixth calculation unit is set to one of the left and right traveling wheels, and the negative acceleration of the rated fixed value is set to the other traveling wheel. A transfer crane characterized by that.

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