1. Product Overview

Various industries have worked to automate transfer tasks in response to recent labor shortages. Many automated transfer carts have been sold in response to this trend, and THK has also commercialized and introduced the transfer robot SIGNAS-BM to the market.

The transfer robot SIGNAS-BM is based on the concept of a reliable transfer robot that can easily be used even in rough environments. It has a simple system for setting up and changing paths, it demonstrates reliable performance when faced with changes in the environment, and maintenance is easy. These characteristics are made possible thanks to the SIGNAS-BM being equipped with a THK-original signpost guidance system that allows the robot to travel at a set speed along a registered path using two cameras on the front to detect markers (signposts) with individual IDs that have been set up along the route.
This signpost guidance system eliminates the need for guide tape that is difficult to maintain and proves cumbersome whenever a path needs to be set or changed. It also allows the SIGNAS-BM to reliably travel across wide spaces or in areas where the surrounding environment has changed.

To allow the system to more fully demonstrate these characteristics, the mechanism itself has been granted greater performance in response to steps, grooves, inclines, and irregular surface conditions.

Fig.1  SIGNAS-BM exterior

Fig.2  Signpost

Fig.3  SIGNAS-BM features

2. Technology Features

The signpost guidance system of the SIGNAS-BM utilizes the following three features to detect signposts placed along the path and control the robot accordingly.

(1) Signposts

The size, material, and patterns used for these proprietary markers were designed to be detected reliably even in environments with a lot of disturbance. The signposts consist of nine black or white square cells in a 3×3 grid, containing parts that indicate both the presence of a signpost and its ID.

(2) Image processing

A filter is applied to images taken by the cameras to extract only the signpost, and its ID is then read so that even if multiple signposts are captured, the system will detect the standard position of the required signpost. Based on the standard position of the signpost detected by the left and right cameras, the robot determines its own position in relation to the signpost.

(3) Travel control

The system controls the robot’s travel along the set path by measuring the distance to the signpost detected by the cameras and the distance of the signpost in relation to the robot’s travel direction. Paths are created by entering and listing movements such as forward, turn, and rotate sequentially on individual lines, so the method for setting paths can be learned quickly.

3. Sales Results

As the demand for automated transfer devices has risen in various industries and more people have learned about this system, an increasing number of units have been sold since September 2020.
Sales results: 100 units (includes 30 units that went to THK or THK Group companies)
Market share：about 1%

4. Conclusion

The SIGNAS-BM requires no guide tape; can travel over rough environments (including steps, grooves, wet surfaces, steel plates, and grating); has easy path configuration; demonstrates reliable performance; and can both carry and pull objects. As a result, more and more companies are choosing SIGNAS-BM as their transfer solution for long distances, between buildings, and wet surfaces, with an increasing number of inquiries coming from the logistics industry (distribution centers) and food industry (food factories).

THK CO., LTD.

2-12-10 Shibaura Minato-ku Tokyo 108-8506 Japan