Patent ID: 8922228

Claim:
A control method of a hybrid-type construction machine for measuring an internal resistance of an electric power accumulator of the hybrid-type construction machine including an engine, an electric generator that assists an output of the engine and generates electricity with the output of the engine, the electric power accumulator, a step-up and step-down transformer, a DC bus, and an inverter that is connected to the step-up and step-down transformer and the electric power accumulator via the DC bus for driving the generator using electric power from the electric power accumulator, the method comprising: a pattern generating step of generating an internal resistance measurement pattern in a non-operation status in which there is no operation for the hybrid-type construction machine from an operator; an output changing step of changing an output of the generator based on the pattern generated in the pattern generating step in the non-operation status such that a state of the electric power accumulator changes from a state where the electric power accumulator is not substantially charged or discharged to a state where the electric power accumulator is charged or discharged; an electric current, etc., detecting step of detecting electric current values and voltage values in the electric power accumulator before and after the change of the output of the generator in the output changing step that causes the step-up and step-down transformer to change the state of the electric power accumulator; and an internal resistance measuring step of measuring the internal resistance of the electric power accumulator based on the electric current values and the voltage values detected before and after the change of state of the electric power accumulator in the electric current, etc., detecting step.