| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device capable of smoothly reducing the assist force during the fail-safe shift as an abnormality occurs in the system, and reducing the loads on a driving circuit and a boosting circuit. SOLUTION: When a system abnormality occurs (YES in Step 101), a microcomputer determines the upper limit power Plim to be reduced as the elapse of time, i.e., the upper limit power Plim which becomes smaller as the elapse of time (Step 102), and successively operates the output power Pout of a boosting circuit (Step 103). The microcomputer further determines whether or not the output power Pout exceeds the upper limit power Plim (Step 104), and drops the output voltage Vout of the boosting circuit (Step 105) so that the output power Pout becomes the upper limit power Plim when the output power Pout exceeds the upper limit power Plim (Pout > Plim, YES in Step 104), in other words, Vout = Plim/Iout. COPYRIGHT: (C)2006,JPO&NCIPI |
