# Research on Welfare Robots: A Multifunctional Assistive Robot and Human-Machine System
## 4 Robot Trial and Discussion
### Discussion  
Elderly people and people with disabilities who have difficulty walking or are unable to walk at all are more likely to develop upper body disuse syndrome. There is a concern that older adults who are otherwise only walking-impaired may become \"bedridden older adults\" and rapidly end up in a bedridden state. Therefore, it is important for people with walking disabilities to actively use their healthy upper body in order to retain as much residual upper body function as possible. The purpose of this study is to promote  
Figure 11: Seated-position walking training.  
Figure 10: Trial use of the multifunctional assistive robot in a restroom.  
Figure 9: Trial in a rehabilitation patient’s room.  
upper body health and improve the self-care ability of people with walking disabilities by assisting their physical function. Recently, various types of welfare equipment for people with walking disabilities have been developed, but most of them have a single function. Equipping small homes with many single-function devices is difficult, and their use is complicated and is not standardized. In this study, we developed a multifunctional assistive robot that integrates mobility, transfer, work support, and training. It is a typical welfare robot.  
Through the trial use of the multifunctional assistive robot in nursing homes, rehabilitation wards, and laboratories, the characteristics of the robot were verified, and the importance of human-machine system construction for the application of welfare robots in real society was recognized.  
The following findings were confirmed regarding the robot's characteristics.  
1. The robot uses omnidirectional movement technology (compact, low-speed, and high-power omni-wheels). Thus, it can move smoothly even in small facilities or private rooms in hospitals. When moving in front of a workbench in a small room, it can easily achieve direct lateral movement rather than rotational advancement.
2. The height of the robot can be adjusted. Thus, it can accommodate users of different heights and adjust to the height of the objects being transferred. Furthermore, it can enable a user to reach objects in high places or on the ground.
3. The seat shape of the robot is narrower at the front than at the back, unlike a normal wheelchair. Thus, the user can sit on the robot in a straddling position, which provides a sense of security and enables the user to flexibly perform various movements.
4. The robot can achieve zero distance between itself and a bed or toilet when transferring.
5. A user can climb on and off easily in a comfortable position.
6. With an orientation sensor attached to the main unit, it can measure the relative relationships between objects and people while moving autonomously within a room and move to its destination while avoiding these obstacles.  
In addition, industrial robots that handle objects are designed for high speed and high efficiency; if their control methods were directly applied to welfare robots, the results would be both unsatisfactory and very dangerous. This paper proposes a method for constructing a human-machine system for welfare robots that includes an estimation of the user's work intention, measurement of riding comfort, and motion generation.  
The multifunctional assistive robot is a typical example of a welfare robot. Through trials of the multifunctional assistive robot in a welfare facility and rehabilitation ward, we observed that a standalone, multifunctional, and independent assistive robot that achieves various support movements should accurately understand the user's intention, actively generate motion, and control it in a manner that is both comfortable and safe for the user.