WORKING VEHICLE AND CONTROL METHOD THEREFOR

A transmission requirement setting unit sets a required traction force in a work vehicle on the basis of an accelerator operation amount. A work implement requirement setting unit sets a required flow rate on the basis of a work implement operation amount. An engine requirement setting unit determines the horsepower required from the engine on the basis of the horsepower required by the transmission set on the basis of the required traction force, and the horsepower required by the work implement set on the basis of the required flow rate. A required throttle setting unit determines a commanded throttle value sent to the engine on the basis of the horsepower required from the engine. A pump displacement setting unit sets a target displacement for the hydraulic pump on the basis of the required flow rate. The work implement requirement setting unit sets an upper limit for the required flow rate to a prescribed flow rate limit value when the discharge pressure of the hydraulic pump is at or above a prescribed pressure threshold.