초록 ▼

The present invention proposes a length measurement method and a length measurement device. The length measurement method includes steps of emitting the laser via a laser ranging module in a reference direction to order to detect a reference distance between a reference point on a target and the las

The present invention proposes a length measurement method and a length measurement device. The length measurement method includes steps of emitting the laser via a laser ranging module in a reference direction to order to detect a reference distance between a reference point on a target and the laser ranging module, taking the reference direction as a the measurement direction, taking the reference distance as a first distance, executing a border detecting procedure according to the measurement direction and the first distance in order to detect a border of the target, and calculating measurement distance between the border and the reference point according to border location information of the laser ranging module corresponding to the border, the reference direction and the reference distance.

대표청구항 ▼

1. A length measurement method, comprising: using a laser ranging module to emit the laser in a reference direction, for detecting a reference distance between a reference point on a subject and the laser ranging module;taking the reference direction as a measurement direction;taking the reference d

1. A length measurement method, comprising: using a laser ranging module to emit the laser in a reference direction, for detecting a reference distance between a reference point on a subject and the laser ranging module;taking the reference direction as a measurement direction;taking the reference distance as a first distance;performing a border detecting procedure in a first detecting direction according to the measurement direction and the first distance for detecting a border of the subject in the first detecting direction; andcalculating a measurement distance between the border and the reference point according to the border corresponding to border location information of the laser ranging module, the reference direction and the reference distance. 2. The length measurement method of claim 1, wherein the border detecting procedure comprises: rotating the measurement direction a first angle around a first axis;using the laser ranging module emitting the laser to a first reflection point in the rotated measurement direction, for detecting the distance between the first reflection point and the laser ranging module;taking the distance between the first reflection point and the laser ranging module as a second distance;determining whether an edge of the subject is detected according to the second distance;determining the border according to the edge if the edge is detected; andtaking the second distance as the first distance, performing the border detecting procedure in the first detecting direction for detecting the border of the subject if the edge is not detected. 3. The length measurement method of claim 2, wherein the step of determining the border according to the edge if the edge is detected comprises: calculating a ratio of the second distance and the reference distance;determining the edge is detected if the ratio is greater than a ratio threshold; anddetermining no edge is detected if the ratio is not greater than the ratio threshold. 4. The length measurement method of claim 2, wherein the step of determining whether the edge of the subject is detected according to the second distance comprises: calculating an absolute value of a first difference between the second distance and the first distance;determining the edge is detected if the absolute value of the first difference is greater than a variation threshold; anddetermining no edge is detected if the absolute value of the first difference is not greater than the variation threshold. 5. The length measurement method of claim 4, wherein the step of determining whether the edge of the subject is detected according to the second distance further comprises: calculating the variation threshold according to the first distance, the measurement direction and the first angle. 6. The length measurement method of claim 2, wherein the border determining procedure comprises: rotating around a second axis, and using the laser ranging module to emit the laser to multiple border determining reflection points in multiple border determining directions, for detecting distances between these border determining reflection points and the laser ranging module, these border determining directions are in line with a second detecting direction;taking the distances between these border determining reflection points and the laser ranging module as multiple border determining distances;determining whether the border of the subject is detected according to the shortest border determining distance of these border determining distances; andtaking the shortest the border determining distance as the first distance, and performing the border detecting procedure for detecting the border of the subject if no border is detected. 7. The length measurement method of claim 6, wherein the step of determining whether the border of the subject is detected according to the shortest border determining distance of these border determining distances comprises: calculating an absolute value of a second difference between the shortest the border determining distance and the second distance; anddetermining the border is detected if the absolute value of the second difference is greater than a variation threshold; anddetermining no border is detected if the absolute value of the second difference is not greater than the variation threshold. 8. The length measurement method of claim 1, wherein the border location information comprises a border direction from the laser ranging module to the border, and the step of calculating a measurement distance between the border and the reference point according to the border corresponding to border location information of the laser ranging module, the reference direction and the reference distance comprises: calculating a angle formed by the border direction and the reference direction; andcalculating the measurement distance according to the angle and the reference distance. 9. The length measurement method of claim 1, wherein the step of calculating a measurement distance between the border and the reference point according to the border corresponding to border location information of the laser ranging module, the reference direction and the reference distance comprises: calculating the measurement distance according to the border distance and the reference distance. 10. A length measurement device, comprising: a laser ranging module; anda control module, electrically connected to the laser ranging module, the control module comprising: a ranging unit, electrically connected to the laser ranging module, arranged to control the laser ranging module to emit the laser in a reference direction, for detecting a reference distance between a reference point on a subject and the laser ranging module;a border detection unit, electrically connected to the ranging unit, arranged to take the reference direction as a measurement direction, the reference distance as a first distance, and performing a border detecting procedure in a first detecting direction for detecting a border of the subject in the first detecting direction; anda calculation unit, electrically connected to the ranging unit and the border detection unit, arranged to calculate a measurement distance between the border and the reference point according to the border corresponding to border location information of the laser ranging module, the reference direction and the reference distance. 11. The length measurement device of claim 10, wherein the border detecting procedure comprises: rotating the measurement direction a first angle around a first axis;using the laser ranging module emitting the laser to a first reflection point in the rotated measurement direction, for detecting the distance between the first reflection point and the laser ranging module;taking the distance between the first reflection point and the laser ranging module as a second distance;determining whether an edge of the subject is detected according to the second distance;determining the border according to the edge if the edge is detected; andtaking the second distance as the first distance, performing the border detecting procedure in the first detecting direction for detecting the border of the subject if the edge is not detected. 12. The length measurement device of claim 11, wherein the control module further comprises a edge determining unit, electrically connected to the border detection unit, and arranged for calculating a ratio of the second distance and the reference distance, determining the edge is detected if the ratio is greater than a ratio threshold, and determining no edge is detected if the ratio is not greater than the ratio threshold. 13. The length measurement device of claim 11, wherein the control module further comprises a edge determining unit, electrically connected to the border detection unit, arranged for calculating an absolute value of a first difference between the second distance and the first distance, determining the edge is detected if the absolute value of the first difference is greater than a variation threshold, and determining no edge is detected if the absolute value of the first difference is not greater than the variation threshold. 14. The length measurement device of claim 13, wherein the control module further comprises a threshold calculation unit, electrically connected to the edge determining unit, arranged for calculating the variation threshold according to the first distance, the measurement direction and the first angle. 15. The length measurement device of claim 11, wherein the control module further comprises a border determining unit, electrically connected to the border detection unit, arranged for performing a border determining procedure to determine the border, the border determining procedure comprises: rotating around a second axis, and using the laser ranging module to emit the laser to multiple border determining reflection points in multiple border determining directions, for detecting distances between these border determining reflection points and the laser ranging module, these border determining directions are in line with a second detecting direction;taking the distances between these border determining reflection points and the laser ranging module as multiple border determining distances;determining whether the border of the subject is detected according to the shortest border determining distance of these border determining distances; andtaking the shortest the border determining distance as the first distance, and performing the border detecting procedure for detecting the border of the subject if no border is detected. 16. The length measurement device of claim 15, wherein the step of determining whether the border of the subject is detected according to the shortest border determining distance of these border determining distances comprises: calculating an absolute value of a second difference between the shortest the border determining distance and the second distance; anddetermining the border is detected if the absolute value of the second difference is greater than a variation threshold; anddetermining no border is detected if the absolute value of the second difference is not greater than the variation threshold.