JPH10212092A - Turning stop control method for turning working machine and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy a plurality of demands on turning stop control with an optimum compromise. SOLUTION: In a control method of this device, a deceleration pattern for attaining a control target serving as a compromise point of a plurality of demands is obtained by an experiment or calculation and stored in a target deceleration setting part 32 of a controller 28. At the time of actual work, suitable one for a working condition at that time is selected out of the stored deceleration pattern to set target deceleration, and control signals are outputted to solenoid proportional pressure reducing valves 26, 27 provided at a pilot line of a turning control valve by the action of a turning body inertial moment computing part 33, a target braking torque computing part 34, a target meter-out pressure computing part 35, a meter-out flow computing part 36, a target meter- out opening area computing part 37 and a control signal computing output part 38 of a controller 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing type working machine having a swing body such as a hydraulic crane and a hydraulic shovel.
The present invention relates to a swing stop control method and an apparatus for automatically stopping a swing body.

[0002]

2. Description of the Related Art In a hydraulic crane, for example, during a turning operation, if a situation (turning angle) occurs in which the vehicle continues to turn without falling due to the outrigger extension state, hanging load, boom undulation angle, etc. In addition, it is necessary to automatically stop the turning operation of the turning body regardless of the operation of the operator.

Alternatively, there is a case where a turning work area is determined in advance, and it is desired to automatically stop turning at a certain turning angle in order to perform a turning operation during this time.

Conventionally, as an automatic stop control method for such a swing body, as disclosed in Japanese Patent Application Laid-Open No. 4-153197, a swing angular acceleration for achieving a desired swing stop control is calculated. Based on the swing angular acceleration, the revolving unit braking torque required for braking the revolving unit is calculated, while the suspension load torque required for braking the suspended load is calculated based on the swing state of the suspended load during the swing braking. A technique has been proposed in which braking is performed based on braking torque.

[0005]

However, in the above-mentioned prior art, since only one control target that does not leave the swing of the suspended load is determined and the turning control is performed only to achieve the control target, other related to the turning stop control. , That is, the condition that the time required for stopping the turning (stop time) is short and the vibration of the revolving body due to the stopping of the turning is small was not sufficiently satisfied.

For example, according to the prior art, the stop time is prolonged by the control only from the viewpoint of ideally setting the swing of the suspended load to zero, and the turning angle to be secured for braking increases accordingly. There is a problem that the area becomes narrow.

SUMMARY OF THE INVENTION The present invention provides a turning stop control method and apparatus for a turning type working machine capable of satisfying a plurality of requirements at the time of turning stop at the best compromise.

[0008]

According to a first aspect of the present invention, there is provided a swing stop control method in which a suspension time required for stopping a swing of a revolving body and a suspended load at the time of the stop of the swing are determined in advance according to work conditions. A deceleration pattern that can achieve a control target as a compromise between a plurality of requests for turning stop control such as a runout amount is set, and when a turning stop command is issued, the deceleration pattern is set from the set deceleration patterns. The target deceleration is set by selecting one that matches the working condition at that time, and the turning braking force is controlled based on the set target deceleration.

The invention of claim 2 (turning control device)
A control valve for controlling the operation of the slewing motor, slewing stop command means for issuing a slewing stop command when the slewing angle of the slewing body reaches a preset braking start angle, and receiving a command from the slewing stop command means. A braking force control means for controlling the control valve to the braking side, and a working condition detecting means for detecting working conditions such as an engine speed and a turning speed, wherein the braking force control means comprises: (i) A deceleration that can achieve a control target as a compromise between a plurality of requests for turning stop control, such as a stop time required to stop the turning of the revolving structure according to work conditions and a swing amount of a suspended load at the time of stopping the turning. Based on a stop command from the stop command unit, a deceleration pattern that matches the work condition at that time detected by the work condition detection unit is selected, and a target deceleration pattern is selected. Target deceleration setting means for setting a degree,
(Ii) Valve control means for calculating a target braking torque required to achieve the set target deceleration and controlling the control valve in a direction to obtain the target braking torque.

According to a third aspect of the present invention, in the configuration of the second aspect, a hydraulic pilot type switching valve is used as the control valve, a turning angular velocity sensor for detecting a turning angular velocity of the revolving body, and a pilot supplied to the control valve. An electromagnetic proportional pressure reducing valve for controlling the pressure; a valve control means for calculating a target meter-out pressure of the control valve from a target braking torque; and a turning angular velocity detected by the turning angular velocity sensor. A meter-out flow rate calculating section for calculating a meter-out flow rate of the control valve from the target meter-out pressure area and a target meter-out opening area calculating section for calculating a target meter-out opening area of the control valve from the target meter-out pressure and the meter-out flow rate. Controls for obtaining the meter-out opening area It calculates a target spool stroke of lube in which and a control signal operation output unit for outputting a control signal for generating the target spool stroke relative to the solenoid proportional pressure reducing valves.

According to a fourth aspect of the present invention, in the configuration of the second or third aspect, there is provided a work state detecting means for detecting a plurality of work states for determining a turning inertia moment of the revolving unit,
The valve control means is configured to calculate a turning moment of inertia of the turning body based on the information from the work state detecting means, and to calculate a target braking torque using the turning moment of inertia.

According to the above method and apparatus, a control target is set as a compromise between a plurality of requirements, such as a small swing of a suspended load at the time of stopping rotation, a short stop time, and a small vibration of a revolving unit. A deceleration pattern for achieving the lever control target is obtained by experiment or calculation, and a target deceleration is set by selecting an appropriate deceleration pattern from actual deceleration patterns during actual work. Since the braking is performed based on the set target deceleration, a plurality of requirements can be satisfied at a high level.

In this case, according to the configuration of claim 4, a plurality of work states (boom length, boom angle, hanging load, etc.) for determining the inertia moment of the revolving unit are detected to obtain the inertia moment of the revolving unit. Since the target braking torque is calculated in consideration of the moment of inertia, control accuracy can be increased as compared with the case where braking is performed based only on the deceleration pattern regardless of the magnitude of the moment of inertia.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.

FIG. 4 shows a schematic configuration of a hydraulic wheel crane according to a preferred embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a lower traveling body, and 2 denotes an upper revolving body (hereinafter, simply referred to as a revolving body) mounted on the lower traveling body 1 so as to be rotatable around a longitudinal axis O. A telescopic boom 3 is provided so as to be able to undulate around a boom foot pin 4. Reference numeral 5 denotes a boom raising and lowering cylinder for raising and lowering the boom 3.

The hoisting rope 7 unreeled from the winch 6 passes through the boom head 3a and is hung on the hanging hook 8, and the suspended load 9 is hung by the hanging hook 8 and raised and lowered.

A swing motor circuit for swinging the swing body 2;
The configuration of a control system for controlling this will be described with reference to FIGS.

In FIG. 1, reference numeral 10 denotes a swing motor, and the rotational force of the swing motor 10 is transmitted to the swing body 2 via a speed reducer 11 and a swing gear (not shown).

A control valve 13 of a hydraulic pilot switching type is provided between the swing motor 10 and a hydraulic pump (hereinafter referred to as a main pump) 12 as a drive source of the motor, and the control valve 13 rotates the swing motor 10. The direction and the speed (the turning direction and the turning speed of the turning body 2) are controlled.

Reference numerals 14 and 14 denote swirl relief valves for restricting swirling pressure, 15, 15 and 16 and 16 denote check valves for preventing backflow, 17 an unload valve, 18 a main relief valve, and 19 a drive of the main pump 12. Engine.

On both side pilot lines 20a and 20b of the control valve 13, electromagnetic remote control valves 21 and 22 for supplying pilot pressure to the control valve 13 are provided.
Is provided. Reference numeral 23 denotes an auxiliary pump as a pilot pressure source.

Reference numeral 24 denotes an operation lever for turning operation. The operation amount of the operation lever 24 is converted into an electric signal by a lever operation amount sensor 25 such as a potentiometer and sent to the remote control valves 21 and 22. Is set to an opening corresponding to the lever operation amount.

Electromagnetic proportional pressure reducing valves (hereinafter, simply referred to as pressure reducing valves) 26 and 27 are provided downstream of the remote control valves 21 and 22 in the pilot lines 20a and 20b, and the secondary pressure from the remote control valves 21 and 22 is provided. Furthermore, this pressure reducing valve 2
The pressure is reduced by 6, 27 and supplied to the control valve 13.

The pressure reducing valves 26 and 27 are controlled by a controller 28.

The controller 28 detects a lever operation amount signal from a lever operation amount sensor 25, an engine speed signal from a speed sensor 29 for detecting the speed of the engine 17, and a turning angular velocity of the swing body 2. Angular velocity signal from the turning angular velocity sensor 30 and the boom hoist cylinder 5
The cylinder pressure signal from the pressure sensor 31 which detects the pressure of the cylinder is input.

Further, as other sensors, sensors (not shown) for detecting a working state, that is, a boom length R, a boom undulation angle θ, and a hanging load W are provided. As shown in FIG. Status information is also input to the controller 28.

The controller 28 includes, as shown in FIG.
Target deceleration setting unit 32, revolving unit inertia moment calculation unit 33, target braking torque calculation unit 34, target meter-out pressure calculation unit 35, meter-out flow rate calculation unit 36, and target meter-out opening area calculation unit 37 And a control signal calculation output unit 38.

The operation of each of these parts will be described.

The target deceleration setting unit 32 includes:
A turning stop command from the turning stop command means 39 is input.

The turning stop instructing means 39 automatically performs a turning operation to prevent a fall from the relation between the rated load and the working state such as the outrigger extension state, the hanging load, the boom length, the boom up / down angle, and the like. An angle that needs to be stopped is set as a braking start angle, and a turning stop command is output when the swing body 2 reaches the braking start angle.

In the target deceleration setting section 32, a plurality of deceleration patterns set in advance according to the working conditions are stored. Select a suitable deceleration pattern and set the target deceleration.

This point will be described in more detail.

When performing the turning stop control, general requirements include that the stopping time required to stop the turning body 2 is short, the swing of the suspended load at the time of stopping the turning is small, There are three points that vibration of the revolving superstructure 2 is small.

However, it is actually impossible to completely satisfy these three requirements at the same time.

Therefore, a control target as a compromise between the three requirements is set in accordance with the working conditions, a deceleration that can achieve this control target is determined by optimization calculation or experiment, and a target deceleration calculation is performed as a deceleration pattern. The information is stored in the unit 32.

Here, a method of obtaining a deceleration pattern by optimization calculation using a mathematical model representing the movement of the crane will be described.

Boom length R: 30.6 m Boom hoisting angle θ: 60 ° Rope length (rope length below the boom head): 29.5 m in a working posture and under the working conditions of cases 1 to 5 shown in Table 1 below. After turning at a constant speed for 20 seconds, assuming that a turning stop command is issued, the target turning angular acceleration AC (t) rad / s ² is determined as a constant deceleration AC rad / s ^2, and the above three requirements are satisfied. The problem of finding a compromise is reduced to the following optimization problem that minimizes the evaluation function J. Using a computer, it is repeatedly calculated by the steepest descent method as an optimization algorithm, and the deceleration AC rad / s ² is determined. Was.

Note that the "steepest descent method" is a method for obtaining a local solution of minF (X).
An algorithm that automatically finds the vector X that minimizes (X). From all directions dX away from the current state X (i), the direction in which F (X) becomes the smallest is selected. Is X (i + 1). In the next state X (i + 1), the same operation is performed to obtain the next state X (XI + 2). In this method, the minimum value of F (X) is obtained by repeating this procedure.

[0040]

[Table 1]

[0041]

J = a1 · | H | + a2 · | T | + a3 | D | where H is the maximum swing amount (cm) of the suspended load after the start of control,
T is the stop time (s), D is the actual deceleration (shock) of the revolving superstructure different from the target deceleration (rad / s ² ), and the weighting factor a
1, a2 and a3 were determined as follows: a1 = 0.01 (H is about 100 cm) a2 = 0.15 (T is about 6 s) a3 = 40 (D is about 0.025 rad / s ² ).

[0042] Then, determine the initial value of the deceleration AC as downtime becomes 10s (rad / s ^2), the optimization calculation result is a following table 2, deceleration AC (rad / s ² ).

[0043]

[Table 2]

At this time, the spool stroke S (t) of the control valve 13 under each working condition is as shown in FIG.

In the above example, cases 1 to 5 are used as working conditions.
Although only the above description has been given, it is needless to say that a deceleration pattern under a larger number of working conditions is obtained in practice.

In the case of a work condition not stored in the target deceleration setting section 32, a deceleration pattern of a work condition close to the work condition is selected, a deceleration is obtained by interpolation calculation, and set as a target deceleration.

Revolving body inertia moment calculating section 33 The calculating section 33 detects the detected work state information (R, θ,
W), the moment of inertia I of the revolving superstructure 2 is calculated,
This moment I is sent to the braking torque calculator 34.

The braking torque calculating section 34 calculates the set target deceleration AC (rad
/ S ² ) and the revolving body inertia moment I, the target braking torque T

[0049]

## EQU2 ## T = I.AC is calculated, and the value is sent to the target meter-out pressure calculating section 35.

The target meter-out pressure calculating section 35 calculates the target meter-out pressure P0 from the target braking torque T and the discharge capacity Q1 per 1 rad of the rotation angle of the turning motor shaft.

[0051]

## EQU3 ## P0 = T / Q1 and the value is calculated as the target meter-out opening area calculation unit 3.
Send to 7.

The meter-out flow rate calculator 36 calculates the meter-out flow rate Q0 from the turning angular velocity ω detected by the turning angular velocity sensor 30 and the motor discharge capacity Q1.

[0053]

## EQU4 ## Q0 = Q1 ・ ω, and this value is calculated as the target meter-out opening area calculating section 37.
Send to

The target meter-out opening area calculating section 37 is based on the target meter-out pressure P
0, the meter-out opening area A of the control valve 13 and the flow coefficient C

[0055]

## EQU5 ## Q0 = C ・ A√P0.

Therefore, the meter-out opening area calculating section 37
Then, the meter-out opening area A is

[0057]

A = Q0 / C√P0, which is sent to the control signal calculation output unit 38.

Control signal calculation output section 38 The control signal calculation output section 38 calculates the target spool stroke S from the spool opening area characteristic of the control valve 13 known in advance.

[0059]

S = f (A), and a control signal for obtaining the target spool stroke S is output to the electromagnetic proportional pressure reducing valve 26 or 27.

As a result, the control valve 13 is set to the target spool stroke S, and the swing motor 10 is braked at the target deceleration, so that the swing body 2 is (a) short stop time according to the intended control target. (B) The swing amount of the suspended load is small, and (c) the revolving unit 2 automatically stops with little vibration.

In the above embodiment, the remote control valve 2
Although the electromagnetic type is used as 1 and 22, a hydraulic remote control valve may be used instead.

[0062]

As described above, according to the present invention, the turning stop control is not performed based on only one control target (for example, eliminating the swing amount of the suspended load) as in the known art, but the turning stop is performed. Determining the deceleration pattern to achieve the control target as a compromise between multiple requirements, such as small swing of the suspended load at the time, short stop time, small vibration of the revolving structure, etc. The target deceleration is set by selecting the deceleration pattern that matches the working conditions at that time, and braking is performed based on the target deceleration. Can be satisfied.

In this case, according to the fourth aspect of the present invention, a plurality of work states (boom length, boom angle, hanging load, etc.) for determining the moment of inertia of the swing body are detected, and the moment of inertia of the swing body is obtained. Since the target braking torque is calculated in consideration of the moment of inertia, control accuracy can be increased as compared with the case where braking is performed based only on the deceleration pattern regardless of the magnitude of the moment of inertia.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a hydraulic circuit and a control system according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control system of the apparatus.

FIG. 3 is a characteristic diagram of time / spool displacement amount optimized for cases 1 to 5 by the apparatus.

FIG. 4 is a diagram showing a schematic configuration of a hydraulic wheel crane.

[Explanation of symbols]

 2 Revolving unit 10 Rotating motor 12 Hydraulic pump 13 Control valve 26, 27 Electromagnetic proportional pressure reducing valve 32 Target deceleration setting unit 33 Revolving unit inertia moment calculating unit 34 Target braking torque calculating unit 35 Target meter-out pressure calculating unit 36 Meter-out flow rate calculating Unit 37 Target meter-out opening area calculation unit 38 Control signal calculation output unit

Claims (4)

[Claims] 1. A control as a compromise between a plurality of requests relating to turning stop control such as a stop time required for turning a revolving body to turn and a swing amount of a suspended load at the time of turning stop according to work conditions in advance. Set a deceleration pattern that can achieve the target, and when a turn stop command is issued, select a deceleration pattern that matches the work condition at that time from among the set deceleration patterns and set the target deceleration And a turning stop control method for the turning type working machine, wherein the turning braking force is controlled based on the set target deceleration. 2. A control valve for controlling the operation of a swing motor, a swing stop command means for issuing a swing stop command when the swing angle of the swing body reaches a preset braking start angle, and the swing stop command means. Braking force control means for controlling the control valve to the braking side in response to a command from the engine, and a work condition detection means for detecting work conditions such as an engine speed and a turning speed, wherein the braking force control means comprises: (I) In advance, a control target as a compromise point of a plurality of requests regarding turning stop control such as a swing time of a suspended load at the time of turning stop and a stop time required to stop turning of the revolving structure according to work conditions is set. A deceleration pattern that can be achieved is stored, and a deceleration pattern that matches the work condition at that time detected by the work condition detection means is determined based on a stop command from the stop command means. Target deceleration setting means for setting a target deceleration by selecting a target braking torque required to achieve the set target deceleration, and setting the control valve to obtain the target braking torque. A turning stop control device for a turning type working machine, comprising a valve control means for controlling the turning operation of the turning type working machine. 3. The swing stop control device for a swing type working machine according to claim 2, wherein a hydraulic pilot type switching valve is used as a control valve, and a swing angular speed sensor for detecting a swing angular speed of the swing body; An electromagnetic proportional pressure reducing valve for controlling the supplied pilot pressure is provided, and the valve control means detects a target meter-out pressure calculating section for calculating a target meter-out pressure of the control valve from a target braking torque, and the turning angular velocity sensor detects the target meter-out pressure. A meter-out flow rate calculating section for calculating a meter-out flow rate of the control valve from the obtained turning angular velocity; and a target meter-out opening area calculating section for calculating a target meter-out opening area of the control valve from the target meter-out pressure and the meter-out flow rate. And to get this target meter-out opening area And a control signal calculation output section for calculating a target spool stroke of the control valve and outputting a control signal for obtaining the target spool stroke to the electromagnetic proportional pressure reducing valve. Turning stop control device. 4. The turning stop control device for a turning type working machine according to claim 2, further comprising a working state detecting means for detecting a plurality of working states for determining a turning moment of inertia of the turning body, and a valve control means. Is configured to calculate a turning moment of inertia of the revolving body based on information from the work state detecting means, and to calculate a target braking torque using the turning moment of inertia. Turn stop control device.