JPH0312177B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the swing of a dredge boat that excavates earth and sand from the bottom of a water body.

When increasing the water depth of a navigation route or anchorage, or when digging a foundation for the construction of an underwater structure, a dredge boat is used to dig up the earth and sand from the bottom of the water. FIG. 1 is a plan view showing the outline of such a dredger. In this figure, 1 is a hull, 2 is a cutter for excavating earth and sand on the bottom of the water, and 3 is a rudder that projects forward of the hull 1, and the cutter 2 is provided at the tip of the rudder. 4 is a rod-shaped spud that extends from the hull 1 to the bottom of the water, and is provided at the rear of the hull 1.
It is configured to serve as a fulcrum when swinging (rocking). 5a and 5b are anchors fixed to the bottom of the water, and each is connected to wires 6a and 6b. 7a and 7b are sheaves (pulleys) provided on the rudder 3, and the wire 6a is wound around the winch drum 8a via the sheave 7a.
The wire 6b is wound around the winch drum 8b via the sheave 7b. DCM1
DCM2 is a DC motor that drives the winch drum 8b via the reducer 9b, and DCM2 is a DC motor that drives the winch drum 8a via the reducer 9a.

When the above-mentioned dredger is to be swung to the right from point B to point A, for example, the wire 6a is wound up by the winch drum 8a while applying a regenerative brake to the DC motor DCM1 and applying appropriate tension to the wire 6b. Rotate it to the point. At the same time, the cutter 2 is used to excavate the bottom of the water for dredging. Then, each time the position of the spud 4 is moved forward (upward in the drawing) little by little, shaking is performed while swinging to the right or to the left, and the entire target area is shaken.

FIG. 2 is a block diagram of a conventional swing control device that controls the swing motion described above. In addition,
In this figure, parts corresponding to those in FIG. 1 are given the same reference numerals.

In this figure, SW1 is a switch that is turned ON when the motor swings to the left, and a speed signal _S1 that commands the rotational speed of the DC motor DCM1 is supplied as an addition signal to the deviation detection point _a1 via this switch SW1. In addition, a DC motor DCM is installed at the deviation detection point _a1 .
The output signal of the indicator generator PG, which outputs a voltage corresponding to the rotation speed of 1, is supplied as a subtraction signal, and the deviation obtained at this deviation detection point a ₁ is sent to the controller.
Supplied to CL ₁ . The controller CL ₁ controls the DC motor DCM based on the deviation obtained at the deviation detection point a ₁
Outputs a signal Sa that commands an armature current value of 1.
In this case, the signal Sa output by the controller CL ₁ is such that the deviation at the deviation detection point a ₁ is O. _SW2 is a switch that contacts contact L when swinging to the left and contact R when swinging right, and its common terminal is connected to deviation detection point _a2 . Deviation detection point a ₂
The feedback value Iaf of the armature current supplied from the current transformer CT is supplied as a subtraction signal, and the signal Sa is set as an addition signal during the left swing, and is set by the variable resistor VL1 during the right swing. Armature current set values (constant values) are each supplied as addition signals. CL ₂ is a forward converter that can switch between forward and reverse based on the deviation obtained at deviation detection point _a2 .
This controller calculates the firing angle of CH and supplies the resulting firing angle signal S _G to the gate pulse generator GPG1. Gate pulse generator GPG
1 supplies a firing pulse GP to the forward converter CH based on the firing angle signal S _G. AC ₁ is the power supply for the armature circuit of the DC motor DCM1. F ₁ is DC motor DCM
1 field winding, and from power supply AC ₂ to thyristor 1
Current is supplied via 5. Note that the common line of the field winding circuit is not shown. _A3 is a deviation detection point, to which the field reference signal D _S is supplied in advance as an addition signal, and the armature voltage feedback signal Va is supplied as a subtraction signal. CL ₃ is calculated when the deviation obtained at deviation detection point a ₃ becomes negative, that is, Va≧DS
A pulse generator GPG gates the firing angle signal to reduce the field current to protect the motor when
In other cases (when Va<DS), a firing angle signal that makes the field current constant is supplied to the gate pulse generator GPG2. The left swing control circuit LS is configured by each of the above-mentioned components.
Further, a right swing control circuit RS is configured in the same manner as the left swing control circuit LS. To describe the correspondence of the main components between the left swing control circuit LS and the right swing control circuit RS, the controller
Controllers CR ₁ to CR ₃ correspond to CL ₁ to CL ₃ , deviation detection points b ₁ to b ₃ correspond to deviation detection points a 1 to a ₃ , respectively, and switches SW ₂ , variable resistor VL 1, and thyristor 15 correspond to controllers CR 1 to CR 3, respectively. SW4, variable resistor VL2,
Thyristors 16 correspond to each. Further, _F2 is a field winding of the DC motor DCM2, and SW3 is a switch that is turned on when swinging to the right.

Next, the operation of the above-mentioned conventional swing control device will be explained using an example when swinging to the left.

When swinging to the left, switch SW1 is ON, SW3
is turned OFF, switch SW2 contacts the L side, and SW4 contacts the L side. As a result, the DC motor DCM
1 rotates based on the speed signal _S1 , and the wire 6b is wound around the winch drum 8b. on the other hand,
The armature current of the DC motor DCM2 is constantly controlled to the armature current value set by the variable resistor VL2, and therefore the DC motor DCM2 rotates in response to the difference between its output torque and the tension of the wire 6a. (normally rotates in the opposite direction) and applies regenerative braking in the swing direction (left side). In this way, the swing control device swings to the left while applying braking on the starboard side of the hull 1 (FIG. 1).

By the way, in the conventional swing control method, the amount of regenerative braking of the non-swing side DC motor is constant. Since the wire angle of the wire 6a is bad and the wire angle of the anti-swing side wire 6b is good, the swing force to the right is insufficient, and the acceleration time of the swing becomes longer, or in extreme cases, the swing may not be possible. It happens.

In view of the above-mentioned circumstances, this invention provides a method for starting the swing of a dredge boat that can perform a smooth start of the swing. A speed increase controller that outputs a speed command signal is provided, and the wire winding speed of the swing side electric motor is set as the current swing speed, and the value obtained by subtracting the speed command value from the current swing speed is greater than a predetermined positive tolerance value. When the output torque of the braking-side electric motor is increased within a range below a predetermined maximum torque, and when the value obtained by subtracting the speed command value from the current swing speed is smaller than a predetermined negative tolerance value,
The present invention is characterized in that the output torque of the braking-side electric motor is reduced within a range equal to or greater than a predetermined minimum torque.

Embodiments of the present invention will be described below based on the drawings.

FIG. 3 is a block diagram showing the configuration of essential parts of an embodiment of the present invention, and in the figure, 30 is a speed increase controller. The speed increase controller 30 sequentially outputs a speed command value Vc based on a speed increase pattern (this pattern is predetermined) that increases with time from the start of the swing. 31 is a torque command device, which outputs a torque command value based on the speed command value Vc, the current swing speed V, and various constants (details will be described later) set by variable resistors VL3 to VL8.
Tc is calculated and a torque command signal _ST corresponding to this torque command value is output. 32 is a converter;
Based on the torque command signal S _T or the torque command signal S _T ′ set by the variable resistor VL9, the armature current value to be passed through the armature of the DC motor DCM1 or DCM2 on the braking side is calculated, and this calculation result is applied to the armature. Output as current signal SIa. That is, the converter 32 converts the torque command signals _ST and _ST ' into an armature current command signal SIa. SW5 is a switch that is turned on when the swing is started and turned off during normal swing operation. Conversely, SW6 is a switch that is turned off when the swing is started and turned on during normal swing movement. Therefore, the braking side DC motor DCM1
(or DCM2) is controlled based on the torque command signal S T ' set by the variable resistor VL9 during normal swing operation, and is controlled based on the torque command signal S _T ' output by the torque command device 31 at the time of swing _startup .
controlled based on Furthermore, the activation control section 33 is configured by each of the above-mentioned components. In this embodiment, two sets of activation control units 33 are provided, and the output signal SIa of the converter 32 of one set is
is supplied to the terminal R of the switch SW2 instead of the output signal of the variable resistor VL1 shown in FIG.
It is supplied to terminal L of switch SW4 in place of the output signal of switch SW4.

Next, the operation of this embodiment will be explained using a right swing operation as an example.

First, when the right swing is started, the switch SW5 shown in FIG. 3 is turned on and the switch SW6 is turned off. Further, the speed command value Vc is sequentially supplied from the speed increase controller 30 to the torque command device 31. and,
The torque command device 31 subtracts the speed command value Vc from the current swing speed V to obtain a difference ΔV. That is, ΔV=V−Vc...(1) is calculated, and if the difference ΔV is larger than the value ΔV ₁ set in advance by variable resistor VL5, torque command value Tc is set by variable resistor VL3. is increased by the value ΔT. That is, Tc←Tc＋ΔT(ΔV＞ΔV ₁ )...(2). This means that if the current swing speed V is larger than the speed command value Vc by a certain amount ΔV ₁ or more, the output torque of the DC motor DCM1 on the braking side (in this case, the left side) is increased, thereby decelerating the current swing speed V. This is to make it happen. Furthermore, if the torque command value Tc obtained by equation (2) exceeds the value T _MAX set by the variable resistor VL8, Tc=T _MAX (3). This is to keep the torque command value Tc within a certain limit. The torque command value Tc thus obtained is converted into a torque command signal _ST by the torque command device 31 and supplied to the converter 32.
Then, the converter 32 converts the torque command signal S _T into the armature current command signal SIA, and the switch SW shown in FIG.
When the controller CL 2 is supplied to the terminal R of the DC motor DCM 1, the controller CL ₂ controls the armature current a of the DC motor DCM 1 to the command value.
The output torque of No. 1 is controlled so as to be equal to the torque command value Tc.

On the other hand, if the difference ΔV given by equation (1) is smaller than the value −ΔV _{2 obtained by inverting the value ΔV 2 set} in advance by the variable resistor VL6, the torque command unit 31
reduces the torque command value Tc by a value ΔT' set in advance by variable resistor VL4. That is, Tc←Tc−ΔT′(ΔV＜−ΔV ₂ )...(4). This means that if the current swing speed V is considerably smaller than the speed command value Vc (that is, the difference is ΔV ₂ or more), the braking side DC motor DCM
This is to weaken the output torque of No. 1 and thereby accelerate the current swing speed V. Furthermore, if the torque command value Tc obtained by equation (4) is smaller than the value T _MIN set by variable resistor VL7, Tc=T _MIN (5). This is to keep the torque command value Tc within a certain limit. The torque command value Tc thus obtained is supplied to the controller _CL2 in the same manner as described above, and is controlled so that the output torque of the DC motor DCM1 is equal to the torque command value Tc.

In this way, swing start is performed while increasing and decreasing the output torque of the braking side DC motor DCM1, and when the current swing speed V reaches a predetermined speed, the swing start control is completed, switch SW5 is turned off, switch SW6 is turned on, and the variable resistance The torque command signal S _T ' from VL9 is supplied to the converter 32, and from then on, the output torque of the braking side DC motor DCM1 is determined by this signal.
The torque is controlled to a constant value corresponding to S _T ′.

In the above embodiment, the control when starting the right swing was described, but the control when starting the left swing is performed in the same way.

As explained above, the present invention controls the output torque of the braking side electric motor at the time of starting the swing based on the difference between the current swing speed and the speed command value. It becomes possible to increase the speed in an accelerating pattern, which provides the advantage of being able to perform a stable swing.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the outline of a drift boat, FIG. 2 is a block diagram showing the structure of a conventional swing control device, and FIG. 3 is a block diagram showing the structure of the main parts of the present embodiment. DCM1, DCM2...DC motor (electric motor), 3
0... Speed increase controller.

Claims (1)

[Claims] 1 In a swing control method for a dredge boat that swings the dredge boat from side to side, a speed increase controller that outputs a speed command signal according to a preset speed increase pattern during swing maneuver near the swing off point is used. If the wire winding speed of the swing side electric motor is set as the current swing speed and the value obtained by subtracting the speed command value from the current swing speed is larger than a predetermined positive value, braking is performed within a range below a predetermined maximum torque. When the output torque of the side motor is increased and the value obtained by subtracting the speed command value from the current swing speed is smaller than a predetermined negative value, the output of the braking side motor is increased within a range of a predetermined minimum torque or more. A swing control method for a dredge boat, characterized by reducing torque.