A method for determining the speed characteristics of an obstacle

Abstract

The present invention discloses a method for determining the speed characteristics of an obstacle, comprising the following steps: the controller scans the obstacle through a lidar within a fixed time; obtains the output value of the lidar; if the output value of the lidar has no offset angle, it is determined that the obstacle is directly in front of the straight-line travel of the overhead suspension crane trolley; if the output value of the lidar has an offset angle, it is determined that the obstacle is on the left or right side of the straight-line travel of the overhead suspension crane trolley; the present invention realizes the acquisition of the position and speed characteristics of the obstacle through a single lidar, and is further used for the overhead suspension crane trolley to better realize following and obstacle avoidance control; reduces the jerks during the operation of the overhead suspension crane trolley, greatly improves the operation efficiency of the overhead suspension crane trolley, and improves the production efficiency of wafers.

Description

Technical Field

[0001] The present invention belongs to the technical field of speed characteristics, and particularly relates to a method for determining the speed characteristics of an obstacle. Background Art

[0002] An automatic material handling system (AMHS) is, as the name implies, a system for handling materials. With the rising labor costs and the increasing degree of intelligence and refinement in production, traditional manual handling between various machines has become a bottleneck in production efficiency and quality. AMHS systems have begun to be popularized in high-end manufacturing industries such as wafer fabs and liquid crystal panel factories, and it is believed that they will enter more production fields in the future.

[0003] In the existing automatic material handling system applied to a wafer fab, an overhead hoist transport (OHT) usually uses a switch output type obstacle avoidance sensor to sense obstacles ahead, that is, in different preset distance ranges, different speed gears are used for following and obstacle avoidance control.

[0004] However, it is found after long-term application that such a control method has a certain effect when facing a stationary obstacle, but once the obstacle ahead is moving, it will cause the OHT to start and stop repeatedly, accompanied by a large sense of jerk, which is very likely to cause damage to the wafers and is not conducive to the efficient operation of the OHT, thus bringing many adverse effects to the actual use. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for determining the speed characteristics of an obstacle, which can obtain the position and speed characteristics of an obstacle through a lidar, reduce the jerk during the operation of the overhead hoist transport, improve the operation efficiency of the overhead hoist transport, and enhance the production efficiency of wafers.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for determining the speed characteristics of an obstacle, comprising the following steps:

[0007] The controller scans the obstacle through a lidar within a fixed time;

[0008] Obtain the output value of the lidar;

[0009] If the output value of the lidar has no offset angle, it is determined that the obstacle is directly in front of the overhead hoist transport moving straight;

[0010] If the output value of the lidar has an offset angle, it is determined that the obstacle is on the left or right side of the overhead hoist transport moving straight.

[0011] Further, if there is no offset angle in the output value of the lidar, the speed Vb of the obstacle is Vb = Va - ((L1 - L0) / Tt); where Tt is the fixed scanning time of the controller, Va is the speed of the overhead suspension crane trolley, L1 is the output value of the lidar in the previous cycle, and L0 is the output value of the lidar in the current cycle.

[0012] Further, if the offset angle of the lidar output value is to the left, it is determined that the obstacle is on the left side of the straight line of the overhead suspension crane trolley, and the speed Vb of the obstacle is Vb = SQRT(A*A + B*B) / Tt, where A = L0*COS(θ0) + Va*Tt - L1*COS(θ1), and B = L0*SIN(θ0) - L1*SIN(θ1);

[0013] If the offset angle of the lidar output value is to the left, it is determined that the obstacle is on the left side of the straight line of the overhead suspension crane trolley, and the speed Vb of the obstacle is Vb = SQRT(A*A + B*B) / Tt, where A = L0*COS(θ0) + Va*Tt*COS(η) - L1*COS(θ1);

[0014] B = L0*SIN(θ0) + Va*Tt*SIN(η) - L1*SIN(θ1).

[0015] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0016] The method for determining the obstacle speed characteristics of the present invention's solution obtains the position and speed characteristics of the obstacle through a single lidar, and is then used to better achieve following and obstacle avoidance control for the overhead suspension crane trolley; it reduces the jerks during the operation of the overhead suspension crane trolley, greatly improves the operation efficiency of the overhead suspension crane trolley, and enhances the production efficiency of the wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following further illustrates the technical solutions of the present invention with reference to the drawings:

[0018] Figure 1 It is a schematic flowchart of a framework of an embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of the state when A and B are on the same track horizontal plane in an embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of another state when A and B are on the same track horizontal plane in an embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of the state when B is in the left offset position of A in an embodiment of the present invention;

[0022] Figure 5 Schematic diagram of the angle between A and B when B is at the left - biased position of A in an embodiment of the present invention;

[0023] Figure 6 Schematic diagram of the state when B is at the right - biased position of A in an embodiment of the present invention;

[0024] Figure 7 Schematic diagram of the angle between A and B when B is at the right - biased position of A in an embodiment of the present invention. Detailed implementation manners

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0026] Refer to Figure 1 , a method for determining the speed characteristics of an obstacle according to an embodiment of the present invention includes the following steps: S10 The controller scans the obstacle through a lidar within a fixed time; S20 Obtain the output value of the lidar; S30 If the output value of the lidar has no offset angle, it is determined that the obstacle is directly in front of the straight - moving overhead suspension crane trolley; S40 If the output value of the lidar has an offset angle, it is determined that the obstacle is on the left or right side of the straight - moving overhead suspension crane trolley.

[0027] Refer to Figures 2-3 , in step S30, if the output value of the lidar has no offset angle, it is determined that the obstacle is directly in front of the straight - moving overhead suspension crane trolley. In this embodiment, A represents the overhead suspension crane trolley and B represents the movable obstacle.

[0028] In this way, when the output value of the lidar has no offset angle, there are two relative states between A and B.

[0029] The first state is that A and B are on the horizontal plane of the same track 1. At this time, the lidar can directly irradiate B to obtain the speed characteristics of the obstacle.

[0030] The other state is that A and B are on the same inclined plane where the track 2 turns to the track 1. At this time, the lidar can also irradiate B to obtain the speed characteristics of the obstacle.

[0031] Among them, the speed of the obstacle Vb = Va - ((L1 - L0) / Tt); Tt is the fixed scanning time of the controller, Va is the speed of the overhead suspension crane trolley, L1 is the output value of the lidar in the previous period, and L0 is the output value of the lidar in the current period.

[0032] In this way, when there is no offset angle in the output value of the lidar, it can be concluded that B is directly in front of A, and the speed characteristics corresponding to B can be calculated. Furthermore, A, that is, the overhead suspension crane trolley in the air, can make corresponding following and obstacle avoidance control steps according to the speed characteristics.

[0033] If there is an offset angle in the output value of the lidar, it means that B is located on the left or right side of A. When the offset angle of the output value of the lidar is on the left side, refer to Figures 4-5 As shown: At this time, A is on the horizontal plane of track 2, and B is on the inclined plane from track 2 to track 1, which means that B is at an angle to the left of A at this time. Then the offset angle of the output value of the lidar is on the left side, so that the speed characteristics and position of the obstacle B can be deduced.

[0034] The speed of obstacle B, Vb = SQRT(A*A + B*B) / Tt;

[0035] where A = L0*COS(θ0) + Va*Tt - L1*COS(θ1), B = L0*SIN(θ0) - L1*SIN(θ1).

[0036] When the offset angle of the output value of the lidar is on the right side, refer to Figures 6-7 As shown: At this time, A is on the inclined plane from track 2 to track 1, and B is on the horizontal plane of track 1, which means that B is at an angle to the right of A at this time. Then the output value of the lidar is also with an offset angle on the left side, so that the speed characteristics and position of the obstacle B can be deduced.

[0037] The speed of obstacle B, Vb = SQRT(A*A + B*B) / Tt,

[0038] where A = L0*COS(θ0) + Va*Tt*COS(η) - L1*COS(θ1),

[0039] B = L0*SIN(θ0) + Va*Tt*SIN(η) - L1*SIN(θ1).

[0040] The method for determining the speed characteristics of the obstacle in the present invention realizes the acquisition of the position and speed characteristics of the obstacle through a lidar, and is further used for the overhead suspension crane trolley to better realize following and obstacle avoidance control; reduces the jerks during the operation of the overhead suspension crane trolley, greatly improves the operation efficiency of the overhead suspension crane trolley, and improves the production efficiency of the wafers.

[0041] The above are only specific application examples of the present invention, which do not constitute any limitation to the protection scope of the present invention. Any technical solutions formed by equivalent transformation or equivalent substitution fall within the scope of the protection of the present invention.

Claims

1. A method for determining the speed characteristics of an obstacle, characterized in that, It includes the following steps: The controller scans the obstacles through the lidar within a fixed time; Obtain the output value of the lidar; If the output value of the lidar has no offset angle, it is determined that the obstacle is directly in front of the straight-line movement of the overhead suspension crane trolley; If the output value of the lidar has an offset angle, it is determined that the obstacle is on the left or right side of the straight-line movement of the overhead suspension crane trolley; If the offset angle of the output value of the lidar is to the left, it is determined that the obstacle is on the left side of the straight-line movement of the overhead suspension crane trolley, and the speed of the obstacle Vb = SQRT(A*A + B*B) / Tt, where A = L0*COS(θ0) + Va*Tt - L1*COS(θ1), B = L0*SIN(θ0) - L1*SIN(θ1); If the offset angle of the output value of the lidar is to the right, it is determined that the obstacle is on the left side of the straight-line movement of the overhead suspension crane trolley, and the speed of the obstacle Vb = SQRT(A*A + B*B) / Tt, where A = L0*COS(θ0) + Va*Tt*COS(η) - L1*COS(θ1); B = L0*SIN(θ0) + Va*Tt*SIN(η) - L1*SIN(θ1); where Tt is the fixed scanning time of the controller, Va is the speed of the overhead suspension crane trolley, L1 is the output value of the lidar in the previous cycle, and L0 is the output value of the lidar in the current cycle.

2. The determination method of the obstacle speed feature according to claim 1, wherein: If the output value of the lidar has no offset angle, the speed of the obstacle Vb = Va - ((L1 - L0) / Tt); where Tt is the fixed scanning time of the controller, Va is the speed of the overhead suspension crane trolley, L1 is the output value of the lidar in the previous cycle, and L0 is the output value of the lidar in the current cycle.

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