| 摘要 |
A hydraulic transmission ( 21 ) has an electric actuator ( 86 ) for changing its output/input rotation speed ratio. A controller ( 90 ) of the actuator memorizes a command current value to the actuator supposing that load is not applied on the hydraulic transmission, and calculates a value of load applied on the hydraulic transmission by calculating a difference between an actual command current value to the actuator and the memorized command current value. A command current value is compensated based on the value of load, and the actuator receives feedback to be controlled. A vehicle may have a differential mechanism ( 10 ), which combines rotation powers on input side and output side of the hydraulic transmission. A detector ( 82 ) detects rotation speed of a main speed change output shaft ( 27 ) serving as an output shaft of the differential mechanism. If the detected rotation speed differs from target rotation speed of the shaft ( 27 ) determined based on operation of a speed change operation tool, the actuator is forcedly controlled. This difference is supposed to be caused by load applied on the hydraulic transmission, whereby the load is calculated. |
