JPH0379668B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an abnormality monitoring device for a detector that detects the rotational position of one of two relatively rotating members with respect to the other member. (Prior Art) A detector that detects the rotation position of one of two members that rotate relative to each other is widely used as a detector that detects the boom rotation position of a construction machine having a boom that can be freely rotated. ing. In this type of construction machinery, the limit of the load that can be tolerated on the construction machine varies depending on the rotational position of the boom, so it is necessary to accurately grasp the rotational position of the boom at all times. Therefore, this type of construction machine is equipped with a plurality of cams that divide the swing area into a plurality of continuous areas, and also generates output codes that are divided into multiple areas and circulate in a sequential order corresponding to the swing area. A detector was used, which was equipped with a switch to detect the swing position of the boom. (Problems with the Prior Art) However, a detector using this type of switch has mechanically operating parts, and there is a risk of failure or disconnection. If a fault or disconnection occurs in the switch, accurate detection results cannot be obtained, and if the detection output is used to activate the safety device of the construction machine, it will be possible to detect if the construction machine is overloaded. However, there was a risk that the safety devices would not operate and the construction machinery would be damaged or fall over. The present invention has been made in view of the above problems, and provides a detector abnormality monitoring device that detects the occurrence of an abnormality in the detector by disrupting the order of detection outputs and displays this. The purpose is to (Means for Solving the Problems) In order to achieve the above object, the detector abnormality monitoring device of the present invention is configured as follows. That is, the detector detects the rotational position of one of two relatively rotating members with respect to the other member, and is designed to generate output codes that sequentially circulate in correspondence to continuous rotational regions divided into a plurality of parts. The constructed detector abnormality monitoring device is composed of an information processing device that receives and processes the detection code of the detector, and a display device that is activated by the output of the information processing device and displays abnormalities, and that displays the information. When the output code from the detector changes, the processing device monitors the difference between the output code before the change and the output code after the change, and determines whether this difference matches the output code difference between adjacent turning regions. The detector is configured to determine whether the detector is normal or abnormal, and output a signal to activate the indicator if the detector is abnormal. (Function) The detector abnormality monitoring device of the present invention configured as described above monitors the difference between the output code before the change and the output code after the change when the output code from the detector changes to detect an abnormality in the detector. The system is configured to determine and detect whether this difference is different from the output code difference in the sequence area or the output code difference at the end of the sequence, so output codes that circulate in a predetermined order are output during normal operation. There is a detector, and if a failure or disconnection occurs in the detection switch of this detector, the output code after the change will be different from the code difference in the normal sequence compared to the output code before the change. Therefore, by monitoring the disturbance in the order of code differences, it is possible to accurately detect an abnormality in the detector. If it is determined that the detector is abnormal, it can output a signal that activates the display to notify the operator. (Embodiment) An example will be described in which an embodiment of the detector abnormality monitoring device of the present invention is applied to detection of a turning area of a boom of a construction machine. Figure 1 shows the boom rotation areas detected by the detector, A, B, C, D, E, F, G, H, respectively.
Eight turning areas are set. Note that CA is the body of a crane or aerial work vehicle, OR is an outrigger device, and BM is a boom. FIG. 2 shows a swing area detector for detecting in which of the swing areas the boom BM is located, and is roughly composed of three cams and three limit switches. That is, the cam x aligns the formation area of the convex periphery to the area angle of the turning areas A, B, C, and D, and the cam y adjusts the forming area of the convex periphery to the turning area A, B, G, In addition, the cam z has two areas where the convex peripheral formation area is aligned with the turning areas A and H, and a part that is aligned with the turning areas D and E on the opposite side. is forming. These three cams x, y, and z are coaxially superimposed with the phase relationship shown in the diagram, and the boom
It is designed to rotate in conjunction with BM. A limit switch is provided on the convex periphery of each cam x, y, z, one in opposition to each cam, and an ON signal is output when the cam is in contact with the convex periphery. Therefore, when the boom BM rotates 360 degrees, the output of each limit switch is 1, 1, OFF, ON signal.
When the signal is expressed as 0, it appears as shown in the truth table below, and by determining the combination of these output signals, it is possible to determine in which swing region the boom BM is present. . As is clear from the above description, the detector is operated as shown in the truth table below as the boom BM rotates.

[Table] Output signals are output in the order according to the output code in forward rotation order (for boom rotation to the right) or reverse rotation order (for boom rotation to the left). FIG. 3 shows a block diagram of the device of the invention. 1 is the above-mentioned turning area detector; 2 is an information processing device using a known microcomputer or the like;
Reference numeral 3 denotes an indicator that indicates the occurrence of a failure. The information processing device 2 takes in the output signals of the turning area detector 1, converts them into code numbers associated with each output signal, reads them, and uses the code numbers to perform arithmetic processing on rearrangements. This is what was done. Note that the code numbers associated with each turning region according to each output signal are assigned positive numbers from 1 to 8 from A to H in descending order. Now, based on FIG. 4, the arithmetic processing flow in the apparatus of the present invention will be explained in detail. First, power the main unit.
When the signal is turned ON, the output signal of the current turning position (indicated by s in the figure) is captured and stored. Next, the output signal (S' in the figure) after a minute time t has elapsed is taken in. Next, compare these two signals S and S', and if it is determined that they are the same signal, it means that the boom BM exists in the same turning area, so the above signal acquisition is repeated and continued. That will happen. If the previous comparison result is not the same signal, the process moves to an abnormality determination step. In this case, the code numbers of the output signals S and S' that have been taken in previously are read out from the storage section, respectively, and the subtraction is performed using the code numbers. As mentioned above, since the code numbers are in the order of positive numbers, the calculated value in a normal case should be an absolute value of 1 regardless of whether the boom BM turns to the right. If the calculation result is 1, the above-mentioned processing is repeated and continued for normal processing. However, if the calculation result is a value other than 1, the next check step is executed. This is the code No. [K(8)] of the final turning area F of the sequence and the code number of the starting turning area A of the sequence.
When checking if there is a transfer between [K(1)],
The current code No. [Ks] is K(1) and the previous code No.
Whether [Ks′] is K(8) or the current code number [Ks] is K(8) and the previous code number [Ks′]
Checks if is K(1). If the result of this check is YES, this means that the boom BM has shifted its rotation area between A and H, so normal processing is executed to restart calculation processing. However, on the other hand, if the results of the above check steps are all NO, an impossible detection result has been obtained, so it is determined that the detector is abnormal, and the display step is executed to display the abnormality. . By executing this display step, the display 3 displays that an abnormality has occurred. Note that in conjunction with this display, it is also possible to ask the user to stop the drive of the main unit. (Effects) The detector abnormality monitoring device of the present invention configured and operated as described above can reliably detect and display abnormalities such as detector failures and disconnections, so that detector abnormalities can be detected by the operator. This has the excellent effect of being able to notify the user as soon as possible and prevent accidents such as damage to construction machinery or falls due to abnormalities in the detector.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram showing the turning area of a crane vehicle or aerial work vehicle to which the device of the present invention is applied, Fig. 2 is a structural diagram of a turning area detector, Fig. 3 is a block diagram of the device of the present invention, and Fig. 4 The figure is a flowchart showing the control contents of the apparatus of the present invention. Detector (turning area detector)...1, information processing device...2, display device...3.

Claims (1)

[Scope of Claims] 1. A detector for detecting the rotational position of one of two relatively rotating members relative to the other member, and an output code that sequentially circulates in correspondence to continuous rotational regions divided into a plurality of parts. An abnormality monitoring device for a detector configured to generate an abnormality, which comprises an information processing device that receives and processes a detection code of the detector, and a display that is activated by the output of the information processing device and displays an abnormality. When the output code from the detector changes, the information processing device monitors the difference between the output code before the change and the output code after the change, and this difference matches the output code difference between adjacent turning regions. 1. An abnormality monitoring device for a detector, characterized in that the detector is configured to determine whether the detector is normal or abnormal based on whether the detector is normal or not, and output a signal for activating the indicator in the case of abnormality. 2. The detector abnormality monitoring device according to claim 1, wherein the detector detects a turning area of a boom in a construction machine having a boom. 3. Abnormality monitoring of a detector according to claim 2, characterized in that the detector is composed of three limit switches operated by a cam and detects eight sections of the boom rotation area. Device.