JP-7856811-B2 - Soil type determination device and soil type determination method

Inventors

• 浅井 洋
• 大西 公平
• 西堀 義行
• 佐藤 公一郎

Assignees

• 慶應義塾
• 株式会社サムシング

Dates

Publication Date

20260511

Application Date

20250327

Priority Date

20240328

Claims (10)

1. A container for holding a sample of soil, which is formed into a lump, to be used for soil type determination, A stirring means for stirring the sample contained in the container, A control means that controls the stirring means based on control parameters for the stirring means, and acquires the response of the sample to the stirring based on said control parameters, A determination means for determining the soil type of the sample based on the sample's response to the agitation, A soil type determination device characterized by comprising the following features.
2. The soil type determination device according to claim 1, characterized in that the determination means determines the fine particle content in the sample based on the sample's response to the agitation.
3. The soil type determination device according to claim 1 or 2, characterized in that the determination means determines the fine-grained content in the sample based on the magnitude of the average rotational torque in the sample's response to the agitation.
4. The soil type determination device according to claim 1 or 2, characterized in that the determination means determines the clay content and silt content in the sample.
5. The soil type determination device according to claim 1 or 2, characterized in that the determination means determines the silt content in the sample based on the relationship between the uniform distribution of the standard deviation of the torque values measured for clay and silt and the uniform content of silt in the sample.
6. The soil type determination device according to claim 5, characterized in that the determination means determines the clay content of the sample by excluding the silt content of the sample from the fine-grained content of the sample.
7. The soil type determination device according to claim 1 or 2, characterized in that the control means controls the rotational speed of the stirring means to a target value, outputs a rotational torque to maintain the target value, and detects the force acting on the stirring means from the sample in accordance with the rotational torque.
8. The soil type determination device according to claim 3, characterized in that the determination means corrects the fine particle content based on the variation in rotational speed during stirring.
9. The soil type determination device according to claim 8, characterized in that the determination means corrects the fine-grained content such that the correction amount based on the variation in rotational speed decreases as the average rotational torque decreases.
10. A method for determining soil type, A storage step involves placing a sample of soil, which is to be used to determine the soil type, into a container, A stirring step in which the sample contained in the container is stirred with a stirring means, A control step of controlling the stirring means based on control parameters for the stirring means and obtaining the response of the sample to the stirring based on said control parameters, A determination step in which the soil type of the sample is determined based on the sample's response to the agitation, A soil type determination method characterized by including the following.

Description

This invention relates to a soil type determination device and a soil type determination method. Traditionally, boring surveys have been conducted to determine soil type. In soil type determination using boring surveys, the soil classification is determined by human judgment based on visual and tactile observations of the soil. In determining these soil classifications, while the particle sizes of gravel and sand can be visually distinguished, the particle sizes of clay and silt are finer and therefore difficult to distinguish visually. Furthermore, Patent Document 1 describes a technique for determining soil type from images of the soil's state before and after vibration. Japanese Patent Publication No. 2018-066613 This is a schematic diagram showing the configuration of a soil type determination device 1 according to one embodiment of the present invention.This is a conceptual diagram illustrating an example of soil classification.This is a schematic diagram showing the hardware configuration of the information processing device 800 that constitutes the control unit 20.This is a block diagram showing the functional configuration of the control unit 20.This is a schematic diagram showing the position and force control algorithms used in the control unit 20.This flowchart shows the flow of the soil type determination process performed by the soil type determination device 1.This is a schematic diagram showing an example of a sample being placed in the sample container 11.This is a schematic diagram showing an example of a sample container 11 with fixing members 12 and 13 and a drive motor 14 installed.This figure shows the sample after it has been stirred.This is a schematic diagram showing the relationship between time and measured torque values.This is a schematic diagram showing the relationship between time and the rotational speed of the drive motor 14.This figure shows the relationship between the fine particle content and the average value of the rotational torque (average rotational torque).This figure shows the relationship between the uniform clay content and the uniform distribution of the standard deviation of the rotational torque value.This figure shows the relationship between the uniform silt content and the uniform distribution of the standard deviation of the rotational torque value.Figure 12 is a diagram that explains the results of the experiment in which high rotational torque values were measured for the soil type.This is a schematic diagram showing the relationship between time and measured torque values.This figure shows the relationship between the fine particle content and the average value of the rotational torque (average rotational torque).This graph plots the average value of the average rotational torque measured up to 25 times.This figure shows the standard deviation of rotational torque values distributed evenly. Embodiments of the present invention will be described below with reference to the drawings. [Basic Concept of the Invention] This invention measures the response (physical quantities such as force, position, and velocity) that a stirring member receives from a sample (for example, a ball-shaped soil mass) during stirring, thereby determining the soil type. At this time, stirring is performed using position and force control technology used for transmitting force and tactile sensation, and the response from the sample (physical quantities such as rotational torque and rotational velocity) is measured using various data (control parameters) used for control during the stirring process. As for position and force control technology, the technology described in International Publication No. 2015/041046 or International Publication No. 2005/109139, which are applications filed by some of the applicants of the present application, can be used. Then, based on the measurement results taken during mixing, the soil composition of the sample (such as the content of fine-grained clay and silt) is determined. The criteria used for this determination are generated based on known soil composition data. Therefore, it becomes possible to determine soil type based on data that closely resembles the tactile sensation (such as touch) that a human would use to make a judgment. Therefore, it becomes possible to realize a soil type determination technology that is more accurate and simpler. Specific embodiments of the present invention will be described below. [Configuration of the soil type determination device] Figure 1 is a schematic diagram showing the configuration of a soil type determination device 1 according to one embodiment of the present invention. As shown in Figure 1, the soil type determination device 1 comprises a stirring unit 10 (stirring means) and a control unit (control means, determination means) 20, and the stirring unit 10 and the control unit 20 are configured to communicate with each other via a wired or wireless communication network. The stirring unit 10 compri