Patent ID: 7818134

Claim:
A method for detecting forward/reverse speeds in a continuously variable transmission, comprising: detecting first and second rotational speeds of an output shaft of the continuously variable transmission; modulating the first and second rotational speeds of the output shaft into a pulse width modulation signal; comparing a pulse width of the pulse width modulation signal with predetermined values, wherein the predetermined values include a first predetermined value, a second predetermined value, a third predetermined value and a fourth predetermined value; and determining whether a vehicle is in a forward speed state or in a reverse speed state based on a result of said comparing; wherein the vehicle is determined to be in the reverse speed state when the pulse width is larger than or equal to the first predetermined value and is smaller than or equal to the second predetermined value, and wherein the vehicle is determined to be in the forward speed state when the pulse width is larger than or equal to the third predetermined value and is smaller than or equal to the fourth predetermined value.