Material testing machine and method for controlling material testing machine

A method for controlling a material testing machine carried out in the material testing machine which includes

• a load mechanism which applies a test force to a test target,
• a measuring instrument which measures a physical quantity of the test target which changes according to the test force or the application of the test force, and
• a control unit which performs a material test on the test target by controlling the test force, a physical quantity of the test target, or a physical quantity acting on the test target to reduce a difference between a predetermined target value and a value measured by the measuring instrument, the method comprising:
• a step of the control unit performing control input for the load mechanism via a low-pass filter;
• a step of the control unit determining, when setting of the low-pass filter is changed, an appropriate control gain based on a control gain within a range where a control system including the load mechanism and the low-pass filter is stable;
• and
• a step of the control unit controlling an operation of the load mechanism by using the appropriate control gain.