Title:
SPEED DETECTION DEVICE
Document Type and Number:
WIPO Patent Application WO/2011/114438
Kind Code:
A1
Abstract:
A speed detection device is provided with a pulse counting unit (107), a pulse timing unit (109), an overflow detection unit (108) for holding an overflow register (OVF), a capture unit (110) for holding the output of the pulse counting unit (107) in a pulse counting register (CN) and holding the output of the pulse timing unit (109) in a pulse timing register (CT), and an operation unit (113) (frequency calculation unit) for reading the pulse counting register (CN), the pulse timing register (CT), and the overflow register (OVF) and calculating a read frequency operation value (F). When the pulse timing unit (109) has overflowed, the operation unit (113) adds a predetermined constant (TCAP) obtained in the cycle of a capture clock (CK_CAP)/the cycle of a timing clock (CK_TIM) to pulse timing data (YT) in the last interrupt to find pulse timing data (XT) that is obtained as a period of time from the last pulse (PE)/the cycle of the timing clock (CK_TIM).
Inventors:
YOSHIKAWA HIROSHI (JP)
Application Number:
PCT/JP2010/054428
Publication Date:
September 22, 2011
Filing Date:
March 16, 2010
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP (JP)
YOSHIKAWA HIROSHI (JP)
YOSHIKAWA HIROSHI (JP)
International Classes:
G01P3/489
Foreign References:
| JPH0618538A | 1994-01-25 | |||
| JPS59214920A | 1984-12-04 | |||
| JP2007045395A | 2007-02-22 |
Attorney, Agent or Firm:
SAKAI, HIROAKI (JP)
Hiroaki Sakai (JP)
Hiroaki Sakai (JP)
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