專利摘要：
A multi-tier limit-angle protection device detects a rotation angle about a rotation axis of a driving apparatus to thereby control the operation of a driving motor of the driving apparatus. The multi-tier limit-angle protection device includes a first-axis potentiometer for generating a first-axis sensing signal, a first-axis limit-angle detecting module for generating a first-axis confirming signal, and a controller. The controller effectuates a first tier protection mechanism by determining whether a limit angle of the rotation axis is exceeded according to the first-axis sensing signal, effectuates a second tier protection mechanism by determining whether the first-axis potentiometer is operating well according to a first-axis confirming signal, and effectuates a third tier protection mechanism through its control over the driving motor. The multi-tier limit-angle protection device features integration of software and hardware to thereby preclude mechanism complexity and provide a multi-tier limit-angle protection mechanism.