JPH0323313B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an interlocking control device for interlockingly controlling a plurality of controlled members, and is suitable for hydraulic excavators, hydraulic cranes, manipulators, etc. that have a plurality of working members.

In machines that drive multiple actuators to perform desired operations, such as hydraulic excavators, hydraulic cranes, manipulators, etc., one or more driven drive systems are activated in response to the movement of the main drive system. There are cases where it is necessary to drive in a certain relationship. For example, in the hydraulic excavator 1 shown in FIG. 1, it is necessary to move the cutting edge point of the bucket belt 2 linearly according to the target trajectory A. Therefore, in order to move the bucket belt attachment point P linearly, the arm 3 The movement of the arm cylinder 4, which is the drive system (primary side) of the boom 5, is detected, and the amount by which the boom cylinder 6, which is the drive system (driven side) of the boom 5, should be moved is determined, and the boom 5 can be driven accordingly. , has been proposed in Japanese Patent Publication No. 50-858. For the displacement y _a of the arm cylinder 4, the second
A displacement _yb of the boom cylinder 6 according to a predetermined function as shown in the figure is determined in advance, and an instruction signal for applying the displacement yb to the boom cylinder 6 is calculated by a calculation device. A block diagram of such a system is shown in FIG. 7 _is an _{instruction input device ; b} is the calculated displacement instruction signal and speed instruction signal, 10 is the driven side drive system,
y _b , y〓 _b are its displacement and velocity. Displacement instruction signal
In many cases, it is sufficient that at least one of x _a , x _b and speed instruction signals x〓 _a , x〓 _b is given to the drive systems 8 and 10 .

In the interlocking control device having such a configuration, wear of one or more of the actuators included in the driving side drive system 8 and the driven side drive system 10 is caused by the end of the stroke of the movable range or the working range limiting condition of the working member. When a predetermined stroke limit (these are collectively referred to as a stroke limit in the present invention) is reached, it is desirable to stop that actuator and at the same time stop other operating actuators. Otherwise, at the stroke limit, the work machine body will perform an operation different from that intended by the operator.

The idea of stopping all other operating actuators when one or more of a plurality of actuators reaches its stroke limit was disclosed in Japanese Patent Publication No. 54-37406 in the field of master-slave control devices. ing. This is done by comparing the displacement signal to each actuator with a value slightly δ larger than the upper limit value of each stroke limit and a value slightly δ smaller than the lower limit value, and when either limit value is exceeded, the total This is to stop the operation of the actuator. The reason for comparing the limit values slightly beyond each stroke limit is that otherwise the stop would be delayed when starting from the stroke limit.

When such a concept is applied to an interlock control device, the following problems arise.

(1) When the stroke limit is reached and the mode changes to stop mode, the interlock control mode will be forcibly switched to the individual operation mode, and the arithmetic unit 9 will be reset, so if you do not input the initial value,
It is not possible to enter interlock control again, and it takes time and effort to perform the operation after reaching the stroke limit until entering the next interlock control.

(2) As mentioned above, the limit value of the calculation device 9 will deviate from the actual stroke limit by δ, so the entire system will be stopped with a deviation of δ between the calculation device 9 and the driven-side controlled member. If the following operation is continued without resetting the arithmetic device 9, the deviation in δ will gradually accumulate, and there is a risk that the arithmetic device 9 and the driven-side controlled member will not move in the same way. be.

An object of the present invention is to solve the above-mentioned problems, and to prevent the engine from stopping when starting at the stroke limit without setting the limit value to a value exceeding the stroke limit by δ, and to prevent the engine from stopping when the stroke limit is reached. It is an object of the present invention to provide an interlock control device that can be easily operated and that does not cause accumulation of misalignment between an arithmetic device and a driven-side controlled member.

In order to achieve this object, the present invention includes a displacement detection means for detecting the displacement of the driving side drive system and the driven side drive system, and a displacement detection means for detecting the displacement of the driving side drive system and the driven side drive system. A speed command detection means detects a speed command to the motor, and inputs the displacement from the displacement detection means and the speed command from the speed command detection means. a logical operation device that determines when a speed command is in a direction exceeding a stroke limit; and a system control means that stops at least one of the driving side drive system and the driven side drive system based on the determination of the logical operation device. It is characterized by having the following.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

FIG. 4 shows an embodiment of the present invention. Components similar to those in FIG. 3 are designated by the same reference numerals. In this embodiment, displacement instruction signals x a , x _b are used as output signals of the instruction input device 7 and the calculation device 9 that represent the desired motion of the controlled object, for example, the motion of linearly moving the tip of the arm of a hydraulic excavator _. is used.

The displacement detection means 11a and 11b are included in the driving side drive system 8 and the driven side drive system 10, and detect displacements y _a and y _b of two actuators that drive controlled members (for example, an arm and a boom). General displacement sensors such as , potentiometers, encoders, etc. are used. Speed command detection means 12a,
12b detects speed command values x〓 _a , x〓 _b from displacement command signals x a , x _b outputted by the command input device 7 and the calculation device 9, and the displacement command signals x _a , x _b are electrical signals _. If so, a differential circuit is used, and if the arithmetic unit 9 is a miniature model similar to the controlled object, it detects the velocity of the model corresponding to the movement of each actuator or detects the displacement of the model, A device is used to differentiate this and find the velocity. When the instruction input device 7 and the arithmetic device 9 are composed of electrical arithmetic circuits, electrical signals corresponding to the speed command values x〓 _a , x〓 _b can often be extracted from these devices 7 and 9. In addition, speed command values x〓 _a , x〓 _b may be given as speed command signals to the drive systems 8 and 10 together with or instead of displacement command signals x _a , x _b , and in these cases, the speed Command detection means 12
There is no need to provide special devices for a and 12b, and it is sufficient to simply have wiring for guiding the speed command values x〓 _a and x〓 _b .

The logical operation device 13 inputs the speed command values x〓 _a , x〓 _b and the displacements y _a , y _b and determines whether one or more of the interlocking actuators will reach the stroke limit and will move beyond the stroke limit. It is determined whether the speed command value x〓 _a or x〓 _b is equal to This is to stop the drive system 8 and the driven drive system 10.

When the instruction input device 7 outputs a displacement instruction signal x _a to the active side drive system 8, the actuator included in the active side drive system 8 is displaced in accordance with the displacement instruction signal x _a , causing the active side controlled member to move. Control. According to the displacement y _a of the actuator, the calculation device 9 calculates the displacement y _b of the actuator included in the driven drive system 10.
is calculated, a displacement instruction signal x _b is output to the driven drive system 10, and the actuator of the driven drive system 10 is displaced. displacement of these actuators
Even if either y _a or y _b reaches the stroke limit, if the speed command value x〓 _a or x〓 _b for the actuator is zero or a value indicating that it will return to within the stroke limit, the logical operation unit 13 By keeping the logic level of the output signal S at 0 and without interrupting the system control means 14a and 14b, the drive systems 8 and 10 are activated according to the displacement instruction signals x _a and x _b .
keep it running. Only when the stroke limit is reached and _the speed command values x〓 _a , x〓 _b indicate movement outside the _stroke limit, the driving side drive system 8 and the driven side drive system 10 are stopped together.

An example of the logic operation device 13 is shown in FIG. The discrimination circuits 21a and 21b are designed to generate logic signals S _a1 and S _b1 which are 1 and 0 when the speed command values x〓 _a and x〓 _b are positive, or 0 when they are negative. That is, S _a1 = 1 (x〓 _a > 0) 0 (x〓 _a 0) S _b1 = 1 (x〓 _b > 0) 0 (x〓 _b ≦0) On the contrary, the discriminator circuits 22a and 22b have the following form. logic signal of
It emits S _a2 and S _b2 .

S _a2 =0 (x〓 _a ≧0) 1 (x〓 _a <0) S _b2 =0 (x〓 _b ≧0) (x〓 _b <0) In addition, the discrimination circuits 23a and 23b determine the displacement y _a of the actuator. , y _b is the upper limit of the stroke limit y _anax , y _bnax
Logic signal that is 1 when it is above and 0 when it is full, S _a3 , S _b3
It is something that emits. That is, S _a3 = 1 (y _a ≧y _yanax ) 0 (y _a < y _anax ) S _b3 = 1 (y _b ≧ y _bnax ) 0 (y _b < y _bnx discriminator circuits 24a and 24b calculate displacement y _a , y It emits logic signals S _a4 and S _b4 which are 1 when the lower limit values _{y anio} , y _bnio of the stroke limit of b or less, and 0 when larger than the lower limit values y anio , y bnio .That is, S _a4 = 0 (y _a > y _anio ) 1 (y _a ≦y _anio ) S _b4 = 0 (y _b > y _bnio ) 1 (y _b ≦y _bnio ) Logic signals S _a1 to S _a4 and S _b1 to _{S b4} are AND gates 2
5 to 28, and the following calculations are performed.

S _a5 = S _a1・S _a3 S _a6 = S _a2・S _a4 S _b5 = S _b1・S _b3 (・indicates logical product) S _b6 = S _b2・S _b4 Logical signal S _a5 , S _a6 , S _b5 ,S _b6 is or gate 29
is input, and the following calculations are performed.

S=S _a5 +S _a6 +S _b5 +S _b6 (+ indicates logical sum) Because of this configuration, the displacement y _a reaches the upper limit value y _anaX of the stroke limit, and the speed command value x〓 _a is positive. At this time, the logic signal S _a5 becomes 1, and therefore the logic level of the output signal S becomes 1, and the system control means 14a, 14b are suddenly cut off, and the driving side drive system 8 and the driven side drive system 10 are stopped. be done. Similarly,
Output when y _a ≦y _anio and x〓 _a > 0, y _a ≧y _bnaX and x〓 _b > 0, or y _b ≦y _bnio and x〓 _b < 0. The signal S becomes 1, and all drive systems 8 and 10
will be stopped.

The logical operation device 13 is not limited to the one shown in FIG. 5, but may be any device that performs a similar function even if it is equivalent to, or somewhat inferior to, the one shown in FIG. It can be easily realized by using electrical comparators, relays, etc., or by using software such as a microcomputer.

Note that the displacement detection means 11a, 11b may detect the speeds _y〓a , _y〓b of the drive systems 8, 10 and integrate them to detect the displacement.

As the normal instruction input device 7, a manual hydraulic directional switching valve is often used. in this case,
The displacement instruction signal x _a and the speed instruction value x〓 _a cannot be clearly indicated. However, instead of detecting the speed command _value The speed command detecting means 12a includes such a type of detecting means because it is possible to determine whether the direction is to exceed the stroke limit or to go back.

In the illustrated embodiment, both the active drive system 8 and the driven drive system 10 are stopped, but the invention is not limited to this. If there is no delay between the driving side drive system 8 and the driven side drive system 10,
The system control means 14b can be omitted. Also,
If the operator can operate while visually observing the movement of the active-side controlled member, the system control means 14a can be omitted.

In the present invention, the displacement and speed commands of the driving side drive system and the driven side drive system include the displacement and speed commands of the driving side controlled member and the driven side controlled member. That is, the displacement detection means and the speed command detection means are
It also includes those that detect displacement and speed commands of controlled members.

As explained above, according to the present invention, when either the driving side drive system or the driven side drive system reaches the stroke limit and the speed command is in a direction exceeding the stroke limit, the driving side drive system Since at least one of the drive system and the driven drive system is stopped in advance, there is no need to set the value exceeding the stroke limit by δ as the limit value of the logical operation device, as in the conventional case.
There is no need to stop when starting at the stroke limit.
In addition, if the speed command is zero at the stroke limit or indicates movement within the stroke limit, there will be no stopping and
It is possible to immediately move on to the next interlocking control, making the operation easier. Furthermore, since there is no deviation in displacement at the stroke limit between the arithmetic device and the driven-side controlled member, there is no possibility that the arithmetic device and the driven-side controlled member will move incorrectly due to accumulation of deviations. can.

[Brief explanation of drawings]

Figure 1 is a front view of a conventional hydraulic excavator, Figure 2 is a diagram showing the relationship between the displacement of the arm cylinder and the displacement of the boom cylinder when the bucket is linked in a straight line, and Figure 3 is a diagram of the conventional interlocking control device. FIG. 4 is a block diagram showing an embodiment of the present invention, and FIG. 5 is a circuit diagram showing an example of a logic operation device according to an embodiment of the present invention. 7... Instruction input device, 8... Main drive side drive system, 9... Arithmetic device, 10... Drive side drive system, 11a, 11b...
Displacement detection means, 12a, 12b...Speed command detection means, 13...Logic operation device, 14a, 14b...System control means, x _a , x _b ...Displacement instruction signal, _x〓a , _x〓b ...Speed command value, y _a , y _b ...displacement.

Claims (1)

[Claims] 1. An instruction input device that outputs an instruction signal, a driving side drive system that controls the driving side based on the instruction signal of the instruction input device, and a driving side drive system that detects at least one of the displacement and speed of the driving side drive system and controls the driven side drive accordingly. In an interlocking control device that includes an arithmetic device that calculates instruction signals for the system and a driven drive system that controls the driven side based on the instruction signals of the arithmetic device, displacement of the main drive side drive system and the driven side drive system is detected. Displacement detection means; Speed command detection means for detecting speed commands to the driving side drive system and the driven side drive system from instruction signals from the instruction input device and the arithmetic unit; Displacement by the displacement detection means and speed command by the speed command detection means. A logical arithmetic device that uses input as input to determine when either the driving side drive system or the driven side drive system has reached the stroke limit and the speed command is in the direction of exceeding the stroke limit; An interlock control device characterized by comprising system control means for stopping at least a predetermined one of the driving side drive system and the driven side drive system.