JPH10212005A - Stacker crane speed controller - Google Patents

Abstract

(57) [Summary] [Problem] To provide a circuit for switching a traveling speed set value stepwise according to a required traveling distance, so that the overall circuit configuration becomes complicated or when the set value is other than the maximum value. Is to improve that the device is not using 100% of its capacity. A traveling speed setting circuit includes only one type of capability limit as a device, an arithmetic circuit for calculating 1/2 of a required traveling distance, and detecting that an actual traveling distance exceeds 1/2. And a setting circuit that sets the deceleration.
A detection circuit for detecting a predetermined deceleration point is provided, and when the traveling distance exceeds 1/2 and the conditions for judging whether or not the deceleration point has been reached are simultaneously satisfied, control is performed so that the traveling speed starts to decelerate. It was done.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed control device for a traveling motor of a stacker / crane, and more particularly to a speed control device capable of reaching a target position in a shortest time. Stacker that can be applied to
The present invention relates to a crane speed control device.

[0002]

2. Description of the Related Art A conventional stacker crane will be described with reference to FIGS. FIG. 3 is a block diagram showing a traveling speed control circuit of a conventional stacker / crane, and FIG. 4 is a characteristic diagram showing traveling characteristics of the circuit of FIG. 3 during traveling. In FIG. 3, 1 is a power supply, 2 is a vector control inverter,
3 is an induction motor, 4 is a dynamic brake circuit that absorbs energy during regenerative operation of the inverter, 5 is a mechanical brake that fixes the induction motor when stopped, 6 is a traveling bogie driven by the induction motor 3, and 7 is an absolute bogie. Absolute encoder for detecting the position, 8 for a pulse generator for detecting the speed of the induction motor 3, 9 for a constant speed control circuit, 10 for an acceleration / deceleration adjustment circuit for raising and lowering the speed of the induction motor 3 at a constant rate to a set value. , 11 is a switching circuit for switching the output signal of the speed setting circuit during running operation and the creep speed setting output signal for making the stop position highly accurate, and 12 is a brake ON for applying and releasing the mechanical brake 5. -OFF circuit, 13 is a creep speed setting circuit,
14 is a traveling starting point detecting circuit for detecting the starting point of the bogie based on the output signal of the absolute encoder 7; 15 is a current position detecting circuit for detecting the position of the traveling bogie based on the output signal of the absolute encoder 7; , An arithmetic circuit for calculating the remaining traveling distance by taking the difference from the actual traveling distance, 18 a deceleration point detection circuit for detecting a deceleration start point, 19 a stop position detection circuit for detecting a stop position, and 20 an upper rank. A traveling target position command circuit for commanding a traveling target position by a signal from the system, a command circuit 21 for controlling operation / stop of the vector inverter,
Reference numeral 22 denotes a calculation circuit for calculating a required traveling distance based on output signals of the traveling target position command circuit 20 and the traveling starting point detection circuit 14, 23 is a control system for controlling the entire stacker / crane, and 24 is an arbitrary length of the required traveling distance. , A speed setting circuit having a function of switching a speed set value during traveling operation based on an output of the necessary traveling distance selection circuit 24, and a required traveling distance selection circuit 2
4 is a deceleration point setting circuit having a function of switching the setting of the deceleration point by the output of 4.

[0003] The speed setting circuit 25 divides the length of the traveling distance into an arbitrary number within a certain range, and switches to a speed setting value according to the traveling distance. The longer the traveling distance, the higher the speed setting value. The deceleration point setting circuit 26 switches the deceleration point according to the traveling distance. The deceleration point is set such that the longer the traveling distance is, the greater the distance from the target position is.

Next, the operation will be described. FIG.
4A and 4B, the horizontal axis represents the traveling time t, the vertical axis in FIG. 4A represents the traveling speed and the output of the absolute encoder, and the vertical axis in FIG. Indicates the distance to the position. The running times on the horizontal axis in FIGS. 4A and 4B are the same. 4 (a) and 4 (b), curves e1 and e3 indicate that the required traveling distances are L1 and L, respectively.
Output of the absolute encoder at the time of 3, v1, v
3 is the traveling speed of the induction motor 3 at L1 and L3, respectively, c1 and c3 are the outputs of the required remaining traveling distance calculation circuit 16 to the target position at the required traveling distances L1 and L3, and d1 and d3 are L1 respectively. , L3 indicate the distance traveled, and r1 and r3 indicate the remaining distances to the target position when L1 and L3, respectively. Here, L1> L3. Also, p1 and p3 indicate target positions when the required traveling distances are L1 and L3, respectively.

At time t = 0, the control system 23
Thus, the target position p3 is given to the traveling target position command circuit 20. If the output of the absolute encoder 7 at time t = 0 is defined as 0 for convenience, the required traveling distance L3 directly indicates the target position p3. Time t
= 0, the running speed v3 starts accelerating and reaches the set speed V3 at t = t1. Thereafter, the vehicle continues to travel at the constant speed V3 until time t3. The output of the absolute encoder 7 increases with a curve e3 similar to the travel distance curve d3.
The output of the absolute encoder 7 is supplied to the remaining required traveling distance calculation circuit (required traveling distance-traveling distance) 16 via the current position detection circuit 15 during traveling, and the output of this computing circuit 16 becomes a curve of c3. Of the remaining required traveling distance r3.

At time t3, the deceleration point detection circuit 18 detects that the value of the arithmetic circuit 16 has reached the predetermined deceleration point D3, activates the switching circuit 11, and causes the creep speed setting circuit 13 to The deceleration is started by switching to the creep speed side to reach the creep speed NC at time t4, and the remaining required traveling distance calculation circuit 16 becomes 0 at time t5. Then, the stop position detection circuit 19 operates, and the inverter operation stop control circuit (START-STOP command circuit) 2
1 operates and the inverter 2 stops. Further, the brake ON-OFF circuit 12 operates and the brake 5 operates at the same time, so that the induction motor 3 and the bogie 6 are completely fixed and stop at the target position.

When the distance to the target position is L1 which is sufficiently larger than L3, the running speed curve becomes like V1, and the constant running speed V1 after time t2 is the speed at the limit of the device capacity. The characteristics of the traveling speed curve v1 are the same as those of the traveling speed curve v3 except that the value of the maximum speed setting V1 and the value of the deceleration point D1 are different.

[0008]

However, such a conventional configuration has a circuit for switching the traveling speed set value stepwise in accordance with the required traveling distance, so that the overall circuit configuration becomes complicated. . On the other hand, when the travel set value is other than the maximum value, 100% of the capacity of the device is not used, and there is a disadvantage that the time to reach the travel target position is lengthened. The present invention has been made in view of the above points, and an object of the present invention is to provide a speed control device for a stack crane which solves these disadvantages.

[0009]

In order to achieve the object, a means for setting the traveling speed is only one type of the capacity limit of the apparatus, and an arithmetic circuit for calculating 1/2 of the required traveling distance. And a detection circuit for detecting that the distance actually traveled exceeds 1/2, a setting circuit for setting a deceleration, and a detection circuit for detecting a predetermined deceleration point.
When the determination condition that the traveling distance exceeds 1/2 and the deceleration point is reached is satisfied, the traveling speed is controlled to start deceleration.

In the present invention, the traveling speed set value is only the maximum value of the capacity limit of the apparatus, and the deceleration point, that is, the position where the deceleration is started when the remaining traveling distance reaches a certain set value or less, is only constant. . When the traveling distance is equal to or more than a certain value, the traveling speed setting is the maximum value of the capability limit of the device, and the traveling speed is set to be the same as the traveling speed v1 shown in FIG. When the traveling distance is short, for example, when it is shorter than the preset deceleration point,
Acceleration is continued to a point exceeding one-half of the traveling distance, and deceleration is started without traveling at a constant speed at a point exceeding one-half. By providing the detection circuit for detecting that the travel distance has exceeded １ ／ as described above, the circuit configuration is simplified, and it is possible to reach the target position in the time when the capacity of the device is at its full capacity. Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0011]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIGS. 2 (a) and 2 (b) are characteristic diagrams showing the characteristics during running of FIG. Those with the same reference numerals as
It is a part that has a function. In FIG. 1, reference numeral 30 denotes a speed setting circuit, 31 denotes an arithmetic circuit for calculating a half of a required traveling distance, 32 denotes a detection circuit for detecting that the traveling distance exceeds 1/2, and 33 denotes a deceleration point. Setting circuit, 34 is 1
A logical AND circuit (AND circuit) of the outputs of the traveling detection circuit 32 and the deceleration point detection circuit 18 is a deceleration point detection circuit.

Next, the operation will be described with reference to FIG. The vertical and horizontal axes have the same contents as in FIG. The curves e1, v1, d1, and r1 are the same as those in FIG. 4. In the case of v1, even if the traveling distance exceeds half of the required distance, the vehicle continues traveling without reaching the deceleration point. Therefore, the running characteristics are the same as in FIG. e4, v4, c4, d4, r4
Are the output e4 of the absolute encoder 7, the traveling speed v4 of the induction motor 3, and the required remaining traveling distance calculation circuit 16 to the target position when 1/2 of the traveling distance is shorter than the predetermined deceleration point. The output c4, the traveled distance d4, and the remaining distance r4 to the destination position are shown.

At time t = 0, the control system 23 gives the traveling target position command circuit 20 a target position p4. At time t = 0, if the output of the absolute encoder 7 is defined as 0 for convenience as in the case of FIG. 4, the necessary traveling distance L4 directly indicates the target position p4. At time t = 0, the traveling speed curve v4 starts to rise, and at t = ta when it reaches １ ／ of the required traveling distance,
The detection circuit 32 that detects the required traveling distance １ ／ or more operates. At time t = t0, since the remaining traveling distance r4 is shorter than the predetermined deceleration point D1, the logic circuit 34 outputs both signals of the deceleration point detection circuit 35 and the detection circuit 32 for detecting the required distance 以上 or more. Upon receiving the signal, the switching circuit 11 operates and the speed setting signal switches to the creep speed setting 13 to start deceleration.

At t = tb, the running curve v4 reaches the creep speed Nc. After the operation at the creep speed Nc, the output curve c4 of the remaining running distance calculation circuit 16 becomes zero at t = tc,
The stop position detecting circuit 19 operates, the inverter operation stop control circuit 21 operates, and the inverter 2 stops. The brake application / release operation circuit 12 also operates, and the brake 5
Operates, the rotation of the induction motor 3 stops, the carriage 6 is completely fixed, and stops at the target position.

[0014] Fig. 4 (a), (b) running characteristics of the prior art
2 and the target position p4 in FIGS. 2 (a) and 2 (b).
Comparing the running curves v3 and v4 and d3 and d4 when is selected at the same position, it will be tomorrow that the time to reach the target position is shorter in the method of the present invention. As described above, according to the configuration of the present invention, regardless of the length of the distance to the target position, the target position can be reached in the minimum time that is at the full capacity of the apparatus. Note that the above circuit configuration can be configured not only by hardware but also by software.

[0016]

As described above, according to the present invention, in the prior art, a plurality of travel setting values and a plurality of deceleration point setting values are required, but the traveling speed setting value has one maximum value of the device capacity limit. Since only one deceleration point is required, the circuit configuration is simplified as compared with the conventional system. In addition, regardless of the length of the distance to the target position, it is possible to reach the target position in a minimum time when the capacity of the apparatus is full, which is extremely useful in practical use.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a characteristic diagram of FIG.

FIG. 3 is a configuration diagram showing an example of the related art.

FIG. 4 is a characteristic diagram of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply 2 Inverter (INV) 3 Induction motor (IM) 4 Dynamic brake circuit (DB) 5 Mechanical brake (MB) 6 Truck 7 Absolute encoder (EC) 8 Pulse generator (PG) 9 Constant speed control circuit (ASR) 10 Addition Deceleration adjustment circuit (ARC) 11 Switching circuit 12 Brake ON-OFF circuit 13 Creep speed setting circuit 14 Travel starting point detection circuit 15 Current position detection circuit 16 Arithmetic circuit 19 Stop position detection circuit 20 Travel target position command circuit 21 Command circuit 22 Calculation Circuit 23 Control system 30 Speed setting circuit 31 Operation circuit 32 Detection circuit 33 Setting circuit 34 AND circuit (AND circuit) 35 Deceleration detection circuit

Claims (1)

[Claims] An absolute encoder position is detected based on an output of an absolute encoder. Driving of the bogie is performed by a speed-controlled motor capable of setting an arbitrary speed. A constant acceleration / deceleration adjustment circuit that moves up and down, a creep speed that performs positioning with high accuracy, and a speed setting circuit for normal operation are performed. The output of the travel target position command circuit determines the movement target position. Calculate the distance to the target position from the output of, and when the distance reaches a predetermined value or less, start deceleration and operate at creep speed, and the output of the absolute encoder corresponds to the target position. A traveling circuit of a stacker / crane that stops an electric motor when the value of the traveling distance is equal to a required value; A detection circuit for detecting that the distance has exceeded 1/2 and a predetermined deceleration point setting circuit are provided, and the detection circuit operates and the distance to the target position is equal to or less than a predetermined value. A speed control device for a stacker / crane, characterized in that deceleration is started when the speed has reached, so that the time to reach the target position is the shortest time of the capacity limit of the device.