ALEXANDRIA, Va., May 26 -- United States Patent no. 12,638,468, issued on May 26, was assigned to Hitachi Ltd. (Tokyo).
"Vehicle speed calculation device and vehicle speed calculation method" was invented by Kazuki Morita (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "In order to achieve improvement in reliability of a speed calculation device included in a railway vehicle while reducing cost increase due to redundancy of a device, a vehicle speed calculation device includes at least two shaft speed sensors, a non-contact speed sensor, a sensor receiving unit that receives at least two first detection values detected by the shaft speed sensor and a second detection value detected by the non-contact sp...