# Development of a Humanoid Nursing Care Robot and Realization of Quantitative Pouring Operation
## 2 Welfare Robots for Older Person Care: About the Nursing Care Robot  
Older persons who are unable to perform certain activities of daily living independently due to declining physical and cognitive functioning require assistance or care. The so-called activities of daily living include mobility, eating, defecation, dressing, washing, bathing, and grooming. Three functions are necessary to maintain health and life: eating and drinking water to maintain physical strength, eliminating waste and toxins from the body, and maintaining body hygiene through bathing. If these three tasks are supported, then older persons requiring care can lead a comfortable life. Welfare robots (nursing care robots) that assist or care for older people with difficulties in daily living can be broadly categorized into two types, those that directly assist or care for older adult people, and those that indirectly provide care based on the assistance of caregivers. The nursing care robots discussed in this article are welfare robots that directly assist or care for older people with difficulties in activities of daily living. Research has been carried out mainly in the following areas:  
(a) Walking assistance for people who are weak in muscle strength and balance. The physiological decline evident in the aging process is mainly manifested in decreased limb flexibility, osteoporosis, and muscle atrophy, which leads to a substantially higher risk of falls and fractures. The weakening of the standing function of older adults caused by disease, muscle weakness, fractures, and falls leads to difficulty in walking and restricts the range of activities, and the physical distress leads to mental depression, which further accelerates the aging of body functions, forming a vicious circle. To utilize the residual walking function of older people with weakened standing function and to prevent the complete loss of walking function of the lower limbs, walking assistance utilizing the residual function of the lower limbs [7,8] and walking assistance that recognizes the intention of the person who needs help with walking [9,10] have been used in the field of walking assistance. (b) Mobility and self-care assistance for people with total walking disability  
If people with total walking disability do not actively use their remaining upper body motor functions, they may be confined to bed for a long period of time, which not only leads to personal suffering, but also creates a burden on the family and society. To fulfill the functions of the upper part of the body and to assist in moving, transferring, and standing up, it is necessary to carry or support the entire body when moving or transferring [11, 12, 13], use mobility assistance [14,15], and provide support for the autonomous work of the upper body, even when the person is unable to walk [16,17]. (c) Dietary assistance and nutritional management  
In the area of meal assistance and nutritional management, studies have been conducted on meal assistance using forks and chopsticks [18], and meal assistance utilizing the residual function of the upper extremities [19]. Meal assistance robots can minimize the time and effort required for caregiver dietary assistance and reduce the workload of care facilities. On the other hand, it can enable older people who need meal assistance to eat independently, thus improving the quality of their dining experience. 4. Excretery assistance  
To sustain life, people need to absorb nutrients from their diet and eliminate waste products from the body. Waste elimination is a prerequisite for nutrient absorption, making excretory functions essential for humans and animals. However, the major differences between humans and animals are that (A) the act of defecation is highly private and not carried out in public, and (B) there is no aversion to waste while it is in the human body, whereas once it is out of the body, it is regarded as alien and creates a strong feeling of disgust. These two points have become ingrained in the culture over time.