Patent ID: 8655620

Claim:
A rotation measuring module used to measure rotation of a target object, the rotation measuring module comprising: a first sensor, installed at one first location of the target object so that when the target object is rotating, the first sensor senses a first centripetal acceleration and a first tangential acceleration; a second sensor, installed at a second location of the target object so that when target object is rotating, the second sensor senses a second centrifugal acceleration and a second tangential acceleration; and a processor, which is connected respectively to the first sensor and the second sensor so as to receive from the first sensor the first centripetal acceleration (a C ) and the first tangential acceleration (a T ), and to receive from the second sensor the second centrifugal acceleration and the second tangential acceleration; meanwhile, the processor follows the following equation 1 and 2 to calculate respectively an angular velocity (ω) and an angular acceleration (α) of the first location and the second location: ω = a C r [ Equation ⁢ ⁢ 1 ] α = a T r [ Equation ⁢ ⁢ 2 ] wherein, r is respectively a distance from the first location and the second location to the rotational center of the target object, next, the processor will follow the following equation 3 to calculate a rotational angle (Δθ) of the target object: Δ ⁢ ⁢ θ = ω · Δ ⁢ ⁢ t + 1 2 ⁢ α · Δ ⁢ ⁢ t 2 [ Equation ⁢ ⁢ 3 ] wherein Δt is a sampling period of the first sensor and the second sensor during the measurement.