Assist device, assist method, and recording medium

An assist method for use of an assist device, the assist device including an upper-body belt to be attached to an upper body of a user, a first belt to be attached to a right knee of the user, a second belt to be attached to a left knee of the user, a first wire that couples the upper-body belt to the first belt, a second wire that couples the upper-body belt to the first belt and that crosses the first wire, a third wire that couples the upper-body belt to the second belt, a fourth wire that couples the upper-body belt to the second belt and that crosses the third wire, a sensor, and a motor coupled to the first wire, the second wire, the third wire, and the fourth wire, the method comprising:

• (a) causing the motor to apply a first tension greater than or equal to a first threshold value to one of the first wire and the second wire at a first time and a second tension greater than or equal to the first threshold value to one of the third wire and the fourth wire at a second time different from the first time when the assist device assists the user with walking;
• and
• (b) causing the motor to apply a third tension greater than or equal to the first threshold value to one of the first wire and the second wire at a third time and a fourth tension greater than or equal to the first threshold value to one of the third wire and the fourth wire at the third time when the assist device detects slacking of the upper-body belt using the sensor.

A non-transitory computer-readable recording medium storing a control program that causes a device including a processor to perform a process, the control program being used in an assist device including an upper-body belt to be attached to an upper body of a user, a first belt to be attached to a right knee of the user, a second belt to be attached to a left knee of the user, a first wire that couples the upper-body belt to the first belt, a second wire that couples the upper-body belt to the first belt and that crosses the first wire, a third wire that couples the upper-body belt to the second belt, a fourth wire that couples the upper-body belt to the second belt and that crosses the third wire, a sensor, and a motor coupled to the first wire, the second wire, the third wire, and the fourth wire, the process comprising:

• (a) causing the motor to apply a first tension greater than or equal to a first threshold value to one of the first wire and the second wire at a first time and a second tension greater than or equal to the first threshold value to one of the third wire and the fourth wire at a second time different from the first time when the assist device assists the user with walking;
• and
• (b) causing the motor to apply a third tension greater than or equal to the first threshold value to one of the first wire and the second wire at a third time and a fourth tension greater than or equal to the first threshold value to one of the third wire and the fourth wire at the third time when the assist device detects slacking of the upper-body belt using the sensor.