Upper limb training system and control method thereof

1. An upper limb training system adapted to an upper limb of a user, comprising:

a main body, comprising:

a training unit configured to be connected to the upper limb; and

a plurality of motors coupled to the training unit; and

a control unit electrically connected to the training unit and the plurality of motors, the control unit calculating a position of an end of the training unit and calculating a plurality of torque intervals respectively corresponding to the plurality of motors according to torques generated by each of the plurality of motors;

wherein, when at least one of the torques generated by the plurality of motors exceeds the corresponding torque interval, and the end of the training unit does not move to a predetermined position, the control unit controls each of the plurality of motors to output a first torque to the training unit;

wherein, when the at least one of the torques generated by the plurality of motors exceeds the corresponding torque interval, and the end of the training unit moves to the predetermined position, the control unit controls each of the plurality of motors to output a second torque to the training unit, so as to drive the end of the training unit to leave the predetermined position.

2. The upper limb training system of claim 1 , further comprising:

a driving unit electrically connected to the training unit, the plurality of motors and the control unit, the driving unit sensing the torques generated by each of the plurality of motors and transmitting a data to the control unit, the data comprising a plurality of sets of the torques generated by each of the plurality of motors corresponding to each movement of the training unit, the control unit calculates the torque intervals corresponding to each of the plurality of motors according to the data, and the control unit driving each of the plurality of motors to output the first torque or the second torque to the training unit through the driving unit.

3. The upper limb training system of claim 2 , wherein an upper bound and a lower bound of one of the torque intervals are defined by a mean torque, a weighting factor and a torque standard deviation of the corresponding motor, the mean torque is a mean value of the plurality of sets of the torques generated by each of the plurality of motors corresponding to the each movement of the training unit, and the torque standard deviation is a standard deviation of the plurality sets of the torques generated by each of the plurality of motors corresponding to the each movement of the training unit.

4. The upper limb training system of claim 1 , wherein a virtual wall is further defined, the virtual wall is configured to be located between a head portion of the user and the end of the training unit, the predetermined position is on or inside the virtual wall with respect to the user, and the end of the training unit leaves the predetermined position to move outside the virtual wall.

5. The upper limb training system of claim 4 , wherein the virtual wall comprises two planes perpendicular to each other or an arc surface.

6. The upper limb training system of claim 4 , wherein the second torque is defined by a gain ratio and an original torque;

wherein, when the end of the training unit is located inside the virtual wall with respect to the user, and a distance between the end of the training unit and the virtual wall is greater than a previously calculated distance therebetween, the gain ratio is defined by an unadjusted gain ratio, the distance, a distance weighting factor, a velocity of the end of the training unit relative to the virtual wall and a velocity weighting factor;

wherein, when the end of the training unit is located inside the virtual wall with respect to the user, and the distance between the end of the training unit and the virtual wall is smaller than the previously calculated distance therebetween, the gain ratio is equal to the unadjusted gain ratio minus a constant value.

7. A control method adapted to the upper limb training system of claim 1 , the control method comprising:

executing a teaching procedure, the teaching procedure comprising connecting the upper limb to the training unit, guiding the training unit to move and recording a moving trajectory; and

executing a replaying procedure, the replaying procedure comprising the training unit driving the upper limb to move, gaining the plurality of torque intervals respectively corresponding to the plurality of motors, and executing a protection mode, the protection mode comprising:

the control unit determining whether the torques generated by each of the plurality of motors exceed the corresponding torque interval;

the control unit calculating the position of the end of the training unit, and determining whether the end of the training unit moves to the predetermined position; and

the control unit controlling each of the plurality of motors to output the first torque or the second torque to the training unit.

8. The control method of claim 7 , wherein the upper limb training system further comprises a driving unit, the driving unit is electrically connected to the training unit, the plurality of motors and the control unit, and the replaying procedure further comprises:

the driving unit sensing the torques generated by each of the plurality of motors and transmitting a data to the control unit, the data comprising a plurality of sets of the torques generated by each of the plurality of motors corresponding to each movement of the training unit; and

the control unit calculating the torque intervals corresponding to each of the plurality of motors according to the data, and driving each of the plurality of motors to output the first torque or the second torque to the training unit through the driving unit.

9. The control method of claim 7 , wherein the protection mode further comprises:

when the control unit determines the at least one of the torques generated by the plurality of motors exceeds the torque interval corresponding to each of the plurality of motors, and the end of the training unit does not move to the predetermined position, the control unit controls each of the plurality of motors to output the first torque to the training unit; and

when the control unit determines the at least one of the torques generated by the plurality of motors exceeds the corresponding torque interval, and the end of the training unit moves to the predetermined position, the control unit controls each of the plurality of motors to output the second torque to the training unit, so as to drive the end of the training unit to leave the predetermined position.

10. The control method of claim 7 , wherein the protection mode further comprises defining a virtual wall configured to be located between a head portion of the user and the end of the training unit, the predetermined position is located on or inside the virtual wall with respect to the user, wherein when the control unit controls each of the plurality of motors to output the second torque to the training unit, the end of the training unit moves outside the virtual wall.