JP2009169556A - Tracing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tracing system that surely detects malfunctions of a machining robot, repeating the same operation at normal time, at all times. <P>SOLUTION: A portable measuring device 10 includes a terrestrial magnetism sensor 11 and acceleration sensor 12, a data processing unit 13 for sampling data from each sensor, and a transmission unit 14 for performing radio transmission of the sampling data. A trace data processor 20 includes: a receiving unit 21 for receiving the sampling data by radio from the transmission unit 14; a feature extracting unit 22 for extracting feature value, on the basis of the sampling data; a standard data accumulating unit 23 for accumulating the feature value at standard conditions, as standard data; a reference unit 24 for comparing the output data from the feature extracting unit 22, with the standard data accumulated in the standard data accumulation unit 23; and a decision unit 25 for deciding the propriety of the traced results, on the basis of reference results of the reference unit 24. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tracing system that detects an abnormality of an operation by continuously tracing the operation of an object that always performs the same operation repeatedly in a normal state, such as a machine robot.

  There are various types of robots, and work robots are arranged on the production line. In a production line for automobiles, a plurality of work robots, transfer robots, and the like are arranged as work robots along the assembly line of the automobile, and the automobile is assembled by the work robot. Even in a work robot, particularly in a work robot, arms are connected via joints.

  In these work robots, from the return position of the arm, the pressing force of the arm, the change in the natural frequency of the arm, the abnormal transmission of the drive unit that drives the arm, the change in the shape of the gripping part provided at the tip of the arm, etc. An abnormality in the work robot is detected.

JP 2005-222226 A JP 59-105112 A

  However, such an abnormality detection of the working robot depends on the operation performed by each robot and lacks versatility. Moreover, in the production line, when a plurality of robots perform assembly work in cooperation with each other, it is difficult to detect the robot causing the delay.

For example, although an abnormality of the motor can be detected by an abnormal current flowing through the drive motor provided in the joint portion of the robot, the abnormality detection is limited to a case where the drive motor is damaged. Therefore, it cannot be determined whether or not the robot is operating normally. Therefore, the following methods can be considered to check the normality of the robot's operation, but there is no effective method.
As a first method, it is conceivable to measure the force pressed by the robot arm with a stress sensor. However, it is not an effective means other than the pushing operation of the arm.
As a second method, when the robot arm repeatedly performs an operation, it may be possible to provide a switch or a sensor at a predetermined position to detect the operation speed of the arm. However, it is possible to detect a delay in the entire operation in one cycle. However, a delay or abnormal vibration in a specific time region within one cycle cannot be detected.
As a third method, it is conceivable to detect an abnormality by attaching an acceleration sensor to the arm of the robot, but at which timing abnormal vibration has occurred or at which position abnormal vibration has occurred. It was difficult to judge.

  On the other hand, a plurality of robots are arranged on the production line, and robot control panels connected to each robot are connected. In order to prevent the two robots from interfering with each other, the intrusion into the exclusively controlled area is controlled by an interlock signal. The timing at which entry is possible / impossible depends on the operation timing of the press machine and other robots, but the transport robot suddenly stops before the exclusive control area and enters a waiting state.

  In view of such problems, the present invention provides a tracing system capable of reliably detecting an abnormality in the operation of an object that always repeats the same operation in a normal state such as a working robot. The purpose is to do.

In order to achieve the above object, the tracing system of the present invention includes a feature extraction unit that extracts features based on sensor data output from a geomagnetic sensor and obtains feature amounts, and standardizes feature amounts in a standard state as a reference. A standard data storage unit that stores data, and a reference unit that compares the output data output from the feature extraction unit with the standard data stored in the standard data storage unit.
As a specific first configuration, the tracing system of the present invention includes a portable measurement device and a trace data processing device, and the portable measurement device samples a geomagnetic sensor and sensor data output from the geomagnetic sensor. A data processing unit, and a transmission unit that wirelessly transmits the sampling data sampled by the data processing unit, the trace data processing device receiving a sampling data transmitted from the transmission unit, a feature extraction unit, A standard data storage unit, a reference unit, and a determination unit that determines the suitability of the trace result based on the result of the reference unit.
As a specific second configuration, the tracing system of the present invention includes a geomagnetic sensor, a data processing unit that samples sensor data output from the geomagnetic sensor, a feature extraction unit, a standard data storage unit, and a reference unit. And a determination unit that determines the suitability of the trace result based on the result of the reference unit, and the portable measurement device outputs a determination result by the determination unit to the outside. Further, the standard data storage unit stores standard data received from the outside.
Preferably, the portable measurement device includes an acceleration sensor, and the data processing unit samples the sensor data output from the geomagnetic sensor and the sensor data output from the acceleration sensor at the same timing.

  According to the present invention, since an abnormal operation of a machine robot or the like can be accurately detected, it is possible to detect a failure of the machine robot at an early stage and cope with it. Therefore, by detecting abnormalities with probabilities and taking countermeasures, production efficiency can be improved and the number of defective products can be reduced. In addition, when a plurality of work robots are interlocked, a robot or the like that causes a delay can be detected, so that the object can be appropriately dealt with. Therefore, the delay as a system can be eliminated.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
(First embodiment)
FIG. 1A is a block configuration diagram of the tracing system 1 according to the first embodiment, and FIG. 1B is a block configuration diagram of a portable measuring device 10 attached to the work robot 2.
The tracing system 1 includes a portable measuring device 10 attached to a working robot 2 as a working robot, and a trace data processing device that detects abnormal operation of the working robot 2 by processing sensor data from the portable measuring device 10. 20 and built from. Although FIG. 1 shows a case where the trace data processing device 20 is provided with the wireless receiver 5 and sensor data from the portable measurement device 10 can be received wirelessly, it is directly received by the receiving unit 21 in the trace data processing device 20. You may make it receive.

The portable measuring device 10 includes a geomagnetic sensor 11, an acceleration sensor 12, a data processing unit 13, and a transmission unit 14.
The geomagnetic sensor 11 detects geomagnetism and outputs it as sensor data to the data processing unit 13 as needed. The acceleration sensor 12 detects acceleration and outputs it as sensor data to the data processing unit 13 as needed. Both the geomagnetic sensor 11 and the acceleration sensor 12 are preferably triaxial sensors. In this case, each sensor data is composed of an x component, a y component, and a z component. The data processing unit 13 converts each analog data from the geomagnetic sensor 11 and the acceleration sensor 12 into digital data at the same timing. When receiving the digital data from the data processing unit 13, the transmission unit 14 transmits the sensor information as needed along with the ID number of the portable measurement device 10. One or more portable measuring devices 10 are provided in the arm portion of the work robot 2. Here, the acceleration sensor 12 may be appropriately provided in accordance with the operation of the work robot 2 and the content of the trace confirmation.

  The trace data processing device 20 includes a reception unit 21, a feature extraction unit 22, a standard data storage unit 23, a reference unit 24, a determination unit 25, a collation result storage unit 26, a warning generation unit 27, and a standard data write processing unit 28. Prepare. Hereinafter, the function of each part will be described.

The receiving unit 21 receives sensor information transmitted from the portable measurement device 10 via the wireless receiver 5.
The feature extraction unit 22 extracts features based on the sensor data obtained by the geomagnetic sensor 11 and / or the acceleration sensor 12 and obtains feature amounts. Specifically, the feature extraction unit 22 extracts a feature based on sensor data included in the sensor information received by the reception unit 21 and obtains a feature amount.
The standard data storage unit 23 stores the feature values in the standard state as a reference as standard data. Specifically, the work robot 2 is normally operated. At that time, the receiving unit 21 receives each sensor data of the geomagnetic sensor 11 and / or the acceleration sensor 12 from the portable measuring device 10 as sensor information, and the feature extracting unit 22 has a feature based on the sensor data included in the sensor information. Extract and obtain the feature value. A plurality of feature amounts are obtained by causing the work robot 2 to perform the same operation and performing this series of processing. Then, the standard data writing processing unit 28 selects standard data serving as a reference from the plurality of feature amounts, averages the plurality of feature amounts, obtains standard data, and writes the standard data in the standard data storage unit 23. Make it. The standard data selection, averaging process, and writing process may be performed through an artificial confirmation process.
The reference unit 24 compares the output data output from the feature extraction unit 22 with the standard data stored in the standard data storage unit 23 when the work robot 2 performs an operation to be inspected, and The comparison result is output to the determination unit 25.
The determination unit 25 receives an input of the comparison result from the reference unit 24 and determines an operation abnormality of the work robot 2.
The collation result accumulation unit 26 accumulates the determination result of the determination unit 25.
When the warning generation unit 27 receives an NG determination from the determination unit 25, the warning generation unit 27 turns on a buzzer or a patrol light to notify the operator.

(Second Embodiment)
FIG. 2A is a block configuration diagram of the tracing system 3 according to the second embodiment, and FIG. 2B is a block configuration diagram of the portable measuring device 30 attached to the work robot 2.
The tracing system 3 shown in FIG. 2 (A) is the same as the tracing system 1 shown in FIG. 1 in that it is composed of the portable measuring device 30 and the trace data processing device 40, but shown in FIG. The difference is that the feature extraction unit 22, the standard data storage unit 23, the reference unit 24, and the determination unit 25 are provided not on the trace data processing device side but on the portable measurement device 30. That is, the portable measuring device 30 includes a geomagnetic sensor 31, an acceleration sensor 32, a data processing unit 33, a feature extraction unit 34, a standard data storage unit 35, a reference unit 36, a determination unit 37, a standard data write processing unit 38, and an output unit. 39. The transmission unit 14 in the first embodiment corresponds to the output unit 39, and can be wirelessly transmitted to the trace data processing device 40 via the wireless receiver 5, or a memory unit (not shown) as necessary. The result of the determination unit 37 can also be stored in and output to the outside by wire.
Further, although not shown, the trace data processing device according to the second embodiment may be incorporated in a control device that controls the working robot 2 or a management device that manages the operation commands of the working robot 2. Good.

(Operation trace check processing)
The operation trace confirmation processing of the work robot 2 by the tracing systems 1 and 3 in the first and second embodiments will be described. Note that the basic operation trace confirmation processing in the first embodiment and the second embodiment is the same, so the following description will be made assuming the case of the first embodiment.

In advance, standard data serving as a reference is stored in the standard data storage unit 23 in the following manner.
The work robot 2 is caused to perform a reference operation. During operation of the work robot 2, the geomagnetic sensor 11 and the acceleration sensor 12 output each sensor data to the data processing unit 13, so that the data processing unit 13 samples at predetermined intervals and outputs the sampling data to the transmission unit 14. Then, it is wirelessly transmitted to the trace data processing device 20 via the wireless receiver 5. At that time, the portable measuring device 10 is transmitted with the ID number. Thereby, the trace data processing device 20 can determine which portable measuring device 10 is the transmitted data. When the reception unit 21 receives the trace data processing device 20 via the wireless receiver 5, the trace data processing device 20 extracts the sensor data from the time series of the sensor data by the feature extraction unit 22. Then, it is artificially determined by the standard data writing processing unit 28 what kind of characteristics the operation confirmation of the work robot 2 is to be performed, and the standard data is stored in the standard data storage unit 23 through artificial selection. At this time, the feature amount including the allowable range is set from the sensor data obtained by causing the work robot 2 to repeatedly perform the same operation.

Next, on the premise that standard data is stored in the standard data storage unit 23, processing for tracing the operation of the work robot 2 is performed in the following manner. At that time, the work robot 2 is going to perform the same operation according to the program.
In the portable measuring device 10, the data processing unit 13 receives each sensor data input from the geomagnetic sensor 11 and the acceleration sensor 12, samples the sensor data at a predetermined sampling frequency, and attaches the ID number of the portable measuring device 10. And output to the transmitter 14. The transmission unit 14 transmits the output data from the data processing unit 13 to the trace data processing device 20 via the wireless receiver 5.
In the trace data processing device 20, the reception unit 21 receives transmission data from the portable measurement device 10 via the wireless receiver 5 and outputs it to the feature extraction unit 22. The feature extraction unit 22 outputs the feature amount obtained by extracting the feature corresponding to the operation of the work robot 2 to the reference unit 24. The reference unit 24 compares the feature amount obtained by the feature extraction unit 22 with the standard data stored in the standard data storage unit 23 and outputs a comparison result to the determination unit 25. The determination unit 25 determines whether the operation of the work robot 2 is normal according to the comparison result in the reference unit 24. Regardless of whether the determination is affirmative or negative, the result is stored in the collation result accumulation unit 26. Only when the determination is negative, the warning generator 27 issues a warning.

The actual tracing process by the tracing system will be further described.
FIG. 3 shows an example of sensor output data transmitted from the portable measuring device 10 to the trace data processing device 20 via the wireless receiver 5, and (A) shows the output waveform of the geomagnetic sensor 11, (B). These are figures which show the output waveform of the acceleration sensor 12. FIG. In each figure, the horizontal axis represents time (× 25 milliseconds), and the vertical axis represents the sensor output value (arbitrary scale). This waveform is an example of trace data for a transfer robot that is linked to a press robot.

In the feature extraction unit 22, the output value of the sensor sent from the portable measurement device 10 as needed is accumulated in a buffer, and the following data processing is performed.
First, one step of the work is separated from the sensor output data sequence stored in the buffer. For example, from a predetermined time in one process and a waveform change pattern, the first period, the second period, the third period, and the fourth period are divided as illustrated. Then, features are extracted from the waveform for each period, and are stored as features in the standard data storage unit 23 via the standard data write processing unit 28.

  At the start of use, since standard data is not stored in the standard data storage unit 23, the work robot 1 performs a reference operation to extract features and obtain feature values. For example, regarding the output value in the Z-axis direction from the geomagnetic sensor 11, “normal value 1” and “normal value 2” that are arm stop times at normal times, and “normal value 3” and “normal values 3” that are respective geomagnetic values. The normal value 4 ”is stored in the standard data storage unit 23 as a normal feature amount. The feature extraction unit 22 is determined in accordance with the operation of the work robot 2. In this example, the feature extraction unit 22 is obtained from the output value of the sensor itself. You may ask. For example, when the rate of change of sensor data is a feature, the feature amount is obtained using a value obtained by performing a differentiation process on the output data string. In addition, since the robot performs a predetermined motion, the output data sequence from the sensor in a constant cycle motion may be averaged every time to obtain standard data. Note that the feature amount may be obtained from a plurality of components as well as one component.

  When tracing is performed by causing the work robot 2 to repeatedly perform a predetermined operation, the feature amount is obtained in the manner of obtaining the standard data from the waveform for each period. Then, in the reference unit 24, the feature amount data extracted by the feature extraction unit 22 and the standard data from the standard data storage unit 23 are matched to determine whether they are the same or similar. Next, the determination unit 25 determines whether or not it is within the allowable range according to the comparison result from the reference unit 24. Therefore, the determination unit 25 includes a determination table as to whether or not it is within an allowable range according to the operation content, and outputs either a positive determination or a negative determination according to the determination table.

  For example, in the waveform of the part circled by a solid line in FIG. 3, that is, at the position of quasi-normal 1, the time during which the arm is stopped is the same as the normal value 1, but the magnitude of the geomagnetism is the normal value 3. It is estimated that there is a slight problem in the movement of the arm. Similarly, in the waveform of the part circled with a dotted line in FIG. 3, that is, in the place of quasi-normal 2, the arm stop time is the same as the normal value 2, but the magnitude of the geomagnetism is smaller than the normal value 4, and then suddenly Since it has changed to normal value 2, it is presumed that the arm stop position is waiting a little before the normal place, and it has moved rapidly to the normal place when it is allowed to return to the normal place. .

  As described above, according to the present invention, the abnormal operation of the work robot can be detected, so that the trouble of the work robot can be detected and dealt with early. For example, the occurrence of abnormal vibration is a mechanical failure of the machine robot, the bending of the arm that sends the sheet metal and the wear of the rubber for sucking the sheet metal are malfunctions leading to the robot failure, and the temporary stop before the interlock part is for the work. Each variation is detected in advance as variations in the processing speed of the robot. Thus, by detecting an abnormality with a high probability, it is possible to cope with a state where no abnormality occurs. Therefore, production efficiency can be improved and the number of defective products can be reduced. Note that the tracing system 3 shown in FIG. 2 can perform the same processing as the tracing system 1 shown in FIG. Further, the present invention can be applied not only to the operation of the work robot 2 but also to a robot programmed to perform a certain operation.

(A) is a block block diagram of the tracing system which concerns on 1st Embodiment, (B) is a block block diagram of the portable measuring device with which a working robot is mounted | worn. (A) is a block block diagram of the tracing system which concerns on 2nd Embodiment, (B) is a block block diagram of the portable measuring device with which a working robot is mounted | worn. The example of the output data of the sensor transmitted to a trace data processing apparatus via a wireless receiver from a portable measuring device is shown, (A) shows the output waveform of a geomagnetic sensor, (B) shows the output waveform of an acceleration sensor. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,3 Tracing system 2 Work robot 5 Wireless receiver 10,30 Portable measuring device 11,31 Geomagnetic sensor 12,32 Acceleration sensor 13,33 Data processing part 14 Transmission part 20,40 Trace data processing device 21,41 Reception Unit 22, 34 Feature extraction unit 23, 35 Standard data storage unit 24, 36 Reference unit 25, 37 Judgment unit 26, 42 Verification result storage unit 27, 43 Warning generation unit 28, 38 Standard data write processing unit

Claims (5)

A feature extraction unit that extracts features based on sensor data output from the geomagnetic sensor and obtains feature amounts;
A standard data accumulator that accumulates feature data in a standard state as a standard as standard data;
A tracing system comprising: a reference unit that compares output data output from the feature extraction unit and standard data stored in the standard data storage unit. Consists of a portable measuring device and a trace data processing device,
The portable measurement device includes the geomagnetic sensor, a data processing unit that samples sensor data output from the geomagnetic sensor, and a transmission unit that wirelessly transmits sampling data sampled by the data processing unit,
The trace data processing device traces based on the reception unit that receives the sampling data transmitted from the transmission unit, the feature extraction unit, the standard data storage unit, the reference unit, and the result of the reference unit. The tracing system according to claim 1, further comprising: a determination unit that determines whether the result is appropriate. Trace results based on the results of the geomagnetic sensor, a data processing unit that samples sensor data output from the geomagnetic sensor, the feature extraction unit, the standard data storage unit, the reference unit, and the reference unit A determination unit for determining the suitability of the portable measuring device,
The tracing system according to claim 1, wherein the portable measurement device outputs a determination result by the determination unit to the outside.   The tracing system according to claim 3, wherein the standard data storage unit stores standard data received from outside. The portable measuring device has an acceleration sensor,
The tracing system according to claim 2 or 3, wherein the data processing unit samples the sensor data output from the geomagnetic sensor and the sensor data output from the acceleration sensor at the same timing.

Images