Riding comfort evaluation method and system for construction machine

Abstract

To provide a riding comfort evaluation method and system capable of probabilistically evaluating a function evaluation with respect to a riding comfort of a human being including ambiguity and preference on the basis of a physical amount.SOLUTION: A method of evaluating a riding comfort which is applied to an operator of a construction machine by vibration generated due to operations of the construction machine, applies vibration by an excitation waveform corresponding to prescribed operations of the construction machine, to a subject for acquiring a riding comfort of the subject, constructs a riding comfort evaluation model using a cumulative logistic regression model on the basis of a human body behavior applied to the subject by the vibration and the acquired riding comfort evaluation, then applies vibration by another excitation waveform being an evaluation object and corresponding to the prescribed operation to the subject, and then uses the riding comfort evaluation model on the basis of the human body behavior applied to the subject by the vibration for evaluating the riding comfort.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method and system for evaluating the ride comfort of a construction machine that generates large vibrations. [Background technology]

[0002] Compared to ordinary passenger cars, the vibration level of construction machinery is much higher, and the crew is exposed to vibration for long periods of time. Since long-term exposure to vibration can affect the physical condition of the crew, the comfort of the operator's ride is important for health and safety.

[0003] Conventionally, the evaluation method for ride comfort of vehicles, including passenger cars, uses as an index the composite vibration acceleration value of the seat surface, backrest, and floor, as specified by the ISO (2631-1:1997) / JIS B 7760-1:2004 standards. However, when a construction machine is used for excavation work, the entire vehicle body moves significantly, causing the seat surface and the buttocks of the human body to move relative to each other, resulting in a large rocking motion of the operator on the seat. In such a situation, the composite vibration acceleration value of the seat surface and floor alone is insufficient to evaluate the actual ride comfort. In other words, in order to accurately evaluate the ride comfort during excavation work, an evaluation method that takes into account not only the machine but also the human body behavior of the operator is required. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2000-121506 A Summary of the Invention [Problem to be solved by the invention]

[0005] Regarding the above-mentioned problem, Patent Document 1 proposes an evaluation method in which vibration experiments are conducted on a large number of people to evaluate the ride comfort of railway vehicles, the vertical acceleration of the head, shoulders, and waist is measured, the vibration acceleration and ride comfort are evaluated on a five-point scale, the values ​​are compiled as ride comfort perception values, and multiple regression analysis is performed to calculate an influence coefficient.

[0006] However, unlike the travel of railroad cars or passenger cars, the working motion of construction machinery involves complex oscillations that include not only the vertical direction but also the front-back and pitch directions, so vertical acceleration alone is insufficient as an explanatory variable for ride comfort. Also, in general linear models that treat the objective variable as a continuous scale, such as multiple regression analysis, there is a concern that results cannot be fully utilized when there is no isometricity between evaluation points, such as in sensory evaluation.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a ride comfort evaluation method and system that can probabilistically evaluate human sensory evaluation of ride comfort, including ambiguity and preferences, from physical quantities. [Means for solving the problem]

[0008] In order to solve the above problems, the method of evaluating the ride comfort that vibrations generated by the operation of a construction machine in this embodiment impart to an operator of the construction machine includes: applying vibrations with an excitation waveform corresponding to a specified operation of the construction machine to a test subject, obtaining a ride comfort evaluation from the test subject, constructing a ride comfort evaluation model using a cumulative logistic regression model from the human body behavior caused by the vibration and the obtained ride comfort evaluation, applying vibrations with a different excitation waveform that corresponds to the specified operation and is to be evaluated, and evaluating the ride comfort using the ride comfort evaluation model from the human body behavior caused by the vibration to the test subject. Effect of the Invention

[0009] According to the present invention, it becomes possible to probabilistically evaluate human sensory evaluation of ride comfort, including ambiguity and personal preference, from physical quantities. Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0010] [Figure 1] 1 is an overall view of a hydraulic excavator, which is an example of a construction machine for which ride comfort is evaluated in the present invention. [Diagram 2] Measuring ride comfort using a mock test. [Diagram 3] FIG. 1 is a block diagram showing a functional configuration of a ride comfort evaluation system according to the present invention. [Figure 4] 1 is an example of a cumulative logistic regression model employed in the present invention. [Diagram 5] 1 is a graph showing the relationship between the vibration waveforms used in the evaluation test and the resulting human body behavior. [Figure 6] 13 is an example of an estimated evaluation result of a ride comfort evaluation using a cumulative logistic regression model in the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Fig. 1 is a diagram showing a hydraulic excavator, which is an example of a construction machine to which the ride comfort evaluation method according to the present invention is applied. The basic structure of a hydraulic excavator is composed of three basic parts: a lower traveling body 5 that travels by driving tracks, an upper rotating body 6 that is rotatably provided on the lower traveling body 5, and a front attachment 7 that is rotatably (upward and downward) attached to the upper rotating body 6. A prime mover 3, a pump unit 4, etc. are mounted on the upper rotating body 6.

[0012] A component that directly generates power to operate a hydraulic excavator is called an actuator. A hydraulic excavator has multiple actuators, but Fig. 1 shows, as an example, an arm cylinder 1 that is an actuator for operating a front attachment 7, and a travel motor 2 that is an actuator for traveling a lower traveling body 5. Note that the construction machine to which the present invention is applicable is not limited to the hydraulic excavator shown in Fig. 1, and various other construction machines such as dump trucks, wheel loaders, and bulldozers can be used.

[0013] The present invention provides a method and system for evaluating the ride comfort of a construction machine operator caused by vibrations generated by the operation of the construction machine such as the hydraulic excavator described above. That is, an evaluation test is conducted to measure the vibrations and ride comfort that are caused by the operation of the construction machine and to clarify the relationship between the two.

[0014] However, the evaluation test can be carried out not only by using an actual construction machine, but also by using a simulator, which is a test device that simulates an actual construction machine.

[0015] Evaluation test overview (1) Vibration evaluation test [Measurement overview] The evaluation test in this embodiment is performed as shown in FIG. 2. That is, the floor plate 10 and the seat 11 of the hydraulic excavator are placed on the hydraulic vibration exciter 9, and the subject 8 is seated there. The subject 8 wears a suit equipped with optical reflective markers for motion capture measurement to measure the behavior of each part of the human body (head, shoulders, chest, waist, legs, etc.). A plurality of infrared cameras 12 for motion capture measurement are installed so as to surround the floor plate 10, the seat 11, and the subject 8. In this state, the hydraulic vibration exciter 9 is operated, and the subject 8 is measured by motion capture, so that a total of 12 types of human body behavior parameters, including the displacement of each part of the human body in six degrees of freedom in the forward / backward, up / down, left / right, pitch, roll, and yaw directions, and the velocity when subjected to vibration, can be obtained. In addition, as described later, a plurality of vibration waveforms are prepared, and the subject evaluates the ride comfort of the vibration as "good", "same", or "bad" in comparison with the vibration by the reference waveform, with respect to a certain reference vibration. To allow participants to evaluate without having to think too hard, it is preferable to provide an intuitive method of recording, such as having a switch at hand and having them answer by the number of times they press it.

[0016] Fig. 3 is a block diagram showing the functional configuration of the ride comfort evaluation system according to this embodiment. As shown in Fig. 3, the ride comfort evaluation system is configured by a computer having the following functional units, a CPU (Central Processing Unit) 106 for executing various processes, a transmission / reception unit 104 for transmitting and receiving data to and from other devices, and a memory 105 for storing various programs / data. The CPU 106 has a measurement unit 101, a model construction unit 102, and an evaluation unit 103 as its functional units. In addition, a vibration device 111 and a camera 112 are connected to the ride comfort evaluation system.

[0017] The measuring unit 101 applies vibrations to the test subject with an excitation waveform corresponding to a predetermined operation of the construction machine, and obtains the test subject's evaluation of the ride comfort. Specifically, the measuring unit 101 is connected to a suit worn by the test subject 8 shown in Fig. 2 and a switch prepared in the hand of the test subject 8, and is capable of measuring the behavior of each part of the test subject 8's body and the ride comfort determined by the test subject 8 pressing the switch.

[0018] The model construction unit 102 constructs a ride comfort evaluation model using a cumulative logistic regression model from the human body behavior caused by vibrations on the test subjects and the ride comfort evaluation determined by the test subjects. Specifically, measurements are taken on multiple test subjects, and an evaluation model is constructed based on the obtained data with the behavior of each body part as an explanatory variable and the ride comfort as a target variable.

[0019] The evaluation unit 103 applies vibrations to the test subject with different excitation waveforms corresponding to a predetermined movement, and evaluates the ride comfort using a ride comfort evaluation model from the human body behavior caused by the vibrations on the test subject.

[0020] The transmitting / receiving unit 104 transmits and receives data to and from external devices, receives input from external devices, and outputs the results of various calculations within the system, etc. Details of this will be described later.

[0021] [Measurement conditions] The excitation waveform uses a reference waveform corresponding to the actual operation of the construction machine and multiple simulated waveforms with parameters such as amplitude and peak frequency changed based on the reference waveform. Here, the reference waveform corresponding to the actual operation of the construction machine refers to a vibration waveform that generates the operation that is considered to be the most standard among the operations. For example, if the operation is a traveling operation, it is a waveform of vibration generated when the construction machine is traveling at a medium speed on a flat and well-maintained road. In addition, multiple simulated waveforms with parameters changed based on the reference waveform are waveforms such as vibration when traveling at high speed on a flat road, vibration when traveling at an arbitrary speed on a road with an uneven surface, vibration when suddenly starting or stopping, etc.

[0022] [Measurement procedure] The sensory evaluation of ride comfort is performed by first exciting a standard waveform and having the subject experience the standard vibration. After that, the simulated waveform with modified parameters is excited, and the subject compares the ride comfort with the simulated waveform and the standard vibration, and evaluates it by judging whether the ride comfort with the simulated waveform is better, equal, or worse than the standard vibration. By making such a three-choice judgment, the variation in subjective sensory evaluations can be reduced. In order to accurately compare with the standard vibration, it is preferable to frequently excite the subject with the standard waveform before exciting the simulated waveform, have the subject check it again, and then excite the subject with the simulated waveform. In addition, the behavior parameters of each body part are also obtained by a motion capture camera at the same time as obtaining the ride comfort evaluation.

[0023] (2) Statistical model construction A statistical analysis is performed on the acquired human body behavior parameters and the results of the ride comfort sensory evaluation. The ride comfort evaluation system of this embodiment is characterized by using a cumulative logistic regression model to evaluate the ride comfort in three ways, "good," "same," and "bad," in comparison with the ride comfort due to the reference vibration. The cumulative logistic model is a model that can handle three or more objective variables by applying a logistic regression model, in which the objective variable is a binary variable, to multiple levels. Note that, in this embodiment, the objective variables that are the evaluation results are three, "good," "same," and "bad," but are not limited to this and may be five, for example, by adding "very good" and "very bad," or may be more than that.

[0024] 4 shows a schematic diagram of the cumulative logistic model used in this embodiment. The horizontal axis Z is a linear combination of explanatory variables shown in the following formula 1. In this embodiment, the horizontal axis Z is a relative index obtained as a result of the analysis and is unitless.

[0025]

number

[0026] Here, in the above formula, β iare the logistic regression coefficients, X i represents the human body behavior parameters that are explanatory variables of the ride comfort. n represents the degree of freedom, which is the number of explanatory variables. And X i is the value obtained by normalizing the RMS (Root Mean Square) of the time history waveform of the human body behavior in the simulated waveform of each subject by the RMS of the time history waveform of the human body behavior in the reference waveform, as shown in the following equation 2. Normalization makes it possible to eliminate the influence of individual differences such as the degree of force applied and posture of each subject.

[0027]

number

[0028] In the above formula, A i is the human body behavior parameter in the simulated waveform, S i represents the human body behavior parameters in the reference waveform. A statistical model for ride comfort evaluation is constructed using a cumulative logistic regression model. First, human body behavior parameters that can statistically be explanatory variables for ride comfort are selected using a stepwise method or other method. Next, the regression curve P of the cumulative logistic regression model that predicts the ride comfort evaluation using the selected explanatory variables is shown in Figure 4. 1 (Z), P 2 (Z) is fitted using a method such as maximum likelihood method to find the optimal regression coefficient β i , α 1 , α 2 Identify P 1 (Z) is the probability that the ride quality is rated as "bad" compared to "equal or good", and P 2 (Z) indicates the probability of the ride comfort being rated as "good" versus "bad or equal," and is expressed by the following formula.

[0029]

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[0030]

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[0031] (3) Estimation of ride comfort rating The estimated statistical model is used to estimate the ride comfort evaluation. First, the reference vibration and the vibration to be evaluated are applied, and the human body behavior, which is the explanatory variable of the ride comfort, is measured. Next, a linear combination Z of the explanatory variables expressed by Equation 1 is calculated. The occurrence probability P 1 (Z), P 2 Find (Z). Find P 1 (Z), P 2 From (Z), the probability of being rated as “bad,” “equal,” or “good” can be calculated using the formula below.

[0032]

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[0033]

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[0034]

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[0035] Fig. 5 is a graph showing the test results in this embodiment. In this embodiment, vibrations represented by the vibration input data shown in Fig. 5(a) were applied to the subject, and as a result, behavior data of each part of the body as shown in Fig. 5(b) to (d) was obtained.

[0036] The vibration input data shown in Fig. 5(a) is a waveform simulating the same motion as a specific motion of a construction machine (for example, a shaking motion of swinging the bucket back and forth) that was simulated in a vibration test previously conducted to build an evaluation model, but is a waveform different from the waveform given in the previous vibration test. In other words, it is an unknown waveform that was not measured in advance in the vibration evaluation test (1) above. However, the explanatory variable (Z in Equation 1) for deriving the objective variable in the specific motion is known from the vibration test previously conducted, and by applying the obtained human body behavior data to this, the results shown in Fig. 6 can be obtained even for unknown waveforms.

[0037] In other words, in the evaluation test of this embodiment, it can be seen that the ride comfort provided to the operator of the construction machine by the vibration used in the test is judged to be "better" in 16% of cases, "equal" in 58% of cases, and "bad" in 26% of cases, compared to the ride comfort of the standard vibration.

[0038] As described above, in this embodiment, in order to construct an evaluation model, a cumulative logistic regression model is used that can handle the ride comfort, which is largely influenced by human subjectivity, as an ordinal scale rather than a continuous scale. This makes it possible to probabilistically estimate the sensory evaluation of the ride comfort from physical quantities, that is, behavior parameters that occur in the human body due to vibration.

[0039] According to the embodiment of the present invention described above, the following advantageous effects are obtained. (1) A method for evaluating the ride comfort that is caused to an operator of a construction machine by vibrations generated in conjunction with the operation of the construction machine in this embodiment includes subjecting a test subject to vibrations having an excitation waveform corresponding to a specified operation of the construction machine, obtaining a ride comfort evaluation from the test subject, constructing a ride comfort evaluation model using a cumulative logistic regression model from the human body behavior caused by the vibration and the obtained ride comfort evaluation, and subjecting the test subject to vibrations having a different excitation waveform that corresponds to the specified operation and is to be evaluated, and evaluating the ride comfort using the ride comfort evaluation model from the human body behavior caused by the vibration.

[0040] The above configuration makes it possible to probabilistically evaluate human sensory evaluation of ride comfort, including ambiguity and personal preference, from physical quantities.

[0041] (2) The ride comfort evaluation model according to the present invention is a model that can estimate the probability that the ride comfort will be evaluated as at least "good," "equal," or "bad" for vibration due to a reference excitation waveform. In this way, when the objective variable that is the evaluation result is a sensory scale that is not continuous, a cumulative logistic regression model such as that of the present invention is useful.

[0042] (3) The ride comfort evaluation model is constructed by performing excitation tests using multiple subjects and multiple excitation waveforms, measuring the body behavior of the subjects in three dimensions for each of one or more body parts, and obtaining body behavior parameters including the displacement or velocity of one or more degrees of freedom of each body part and a ride comfort sensory evaluation. The cumulative logistic regression model of the present invention is specifically constructed in this manner.

[0043] (4) When constructing a ride comfort evaluation model, a large number of human body behaviors and ride comfort sensory evaluations collected from multiple subjects are statistically analyzed, and one or more human body behavior parameters that are significant for ride comfort evaluation are selected.

[0044] (5) The selected significant human behavior parameters are used to identify regression coefficients in a cumulative logistic regression model.

[0045] (6) Regression curve P of the cumulative logistic regression model 1 (Z), P 2 (Z) is the following formula:

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[0046] (7) The ride quality evaluation system according to this embodiment also provides the same effects as the methods described above in (1) to (6).

[0047] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the configurations described. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete a part of the configuration of each embodiment, or to add or replace another configuration. [Explanation of symbols]

[0048] 8 Subject (operator), 12 Infrared camera, 100 Evaluation system, 101 Measurement section, 102 Model construction section, 103 Evaluation section

Claims

1. A method for evaluating a ride comfort that is caused to an operator of a construction machine by vibrations generated in association with the operation of the construction machine, comprising the steps of: applying vibrations to a test subject based on a vibration waveform corresponding to a predetermined operation of the construction machine, and obtaining a ride comfort evaluation from the test subject; constructing a ride comfort evaluation model using a cumulative logistic regression model from the human body behavior caused by the vibration on the subject and the acquired ride comfort evaluation; applying a vibration to a test subject according to a different vibration waveform to be evaluated, the vibration corresponding to the predetermined motion, and evaluating the ride comfort using the ride comfort evaluation model based on the human body behavior of the test subject caused by the vibration; A method for evaluating ride comfort.

2. The ride comfort evaluation method according to claim 1, The ride comfort evaluation model is a model capable of estimating the probability that the ride comfort evaluation will be at least “good”, “equal”, or “poor” with respect to the vibration due to the reference vibration waveform. A method for evaluating ride comfort.

3. The ride comfort evaluation method according to claim 1, The ride comfort evaluation model is constructed by performing a vibration test using a plurality of subjects and a plurality of excitation waveforms, measuring the human body behavior of the subjects in three dimensions for each of one or more body parts, and acquiring human body behavior parameters including the displacement or velocity of one or more degrees of freedom of each body part and a ride comfort sensory evaluation. A method for evaluating ride comfort.

4. The ride comfort evaluation method according to claim 3, When constructing the ride comfort evaluation model, a large number of human body behaviors and ride comfort sensory evaluations collected from the plurality of subjects are statistically analyzed, and one or more human body behavior parameters that are significant for the ride comfort evaluation are selected. A method for evaluating ride comfort.

5. The ride comfort evaluation method according to claim 4, identifying regression coefficients in the cumulative logistic regression model using the selected significant human behavior parameters; A method for evaluating ride comfort.

6. The ride comfort evaluation method according to claim 1, The regression curve P of the cumulative logistic regression model １ (Z), P ２ (Z) has the following formula: [0010] [0025] [0030] [0045] (However, P １ (Z) is the probability that the ride comfort is rated as "bad" compared to "equal or good", P ２ (Z) is the probability of the ride quality being evaluated as "good" versus "bad or equal," Z is a linear combination of explanatory variables, and β ｉ is the logistic regression coefficient, X ｉ is the human body behavior parameter that is the explanatory variable of the ride comfort, n is the degree of freedom, A ｉ is the human body behavior parameter in the simulated waveform, S ｉ represents the human body behavior parameters in the reference waveform.) Represented by A method for evaluating ride comfort.

7. A system including a CPU and a memory for evaluating a ride comfort that is caused to an operator of a construction machine by vibrations generated in association with the operation of the construction machine, the system comprising: a measurement unit that applies vibrations based on an excitation waveform corresponding to a predetermined operation of the construction machine to a test subject and obtains a ride comfort evaluation from the test subject; a model construction unit that constructs a ride comfort evaluation model using a cumulative logistic regression model from the human body behavior caused by the vibration of the subject and the acquired ride comfort evaluation; and an evaluation unit that applies a vibration to a test subject according to another vibration waveform to be evaluated, the vibration corresponding to the predetermined motion, and evaluates the ride comfort using the ride comfort evaluation model based on the human body behavior of the test subject caused by the vibration. A ride comfort evaluation system.

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