Chassis dynamometer and method of controlling chassis dynamometer

A method of controlling a chassis dynamometer including four rollers on which four tires of a vehicle are placed, the four tires including a front-wheel tire pair and a rear-wheel tire pair, one of the front-wheel tire pair and the rear-wheel tire pair being defined as a first-type tire pair, and the other of the front-wheel tire pair and the rear-wheel tire pair being defined as a second-type tire pair, the first-type tire pair including a first-type left tire and a first-type right tire that are disposed at both sides, the second-type tire pair including a second-type left tire and a second-type right tire that are disposed at both sides, the four rollers including a first-type left roller on which the first-type left tire is placed, a first-type right roller on which the first-type right tire is placed, a second-type left roller on which the second-type left tire is placed, and a second-type right roller on which the second-type right tire is placed, the four rollers being rotationally driven based on four roller driving commands, the chassis dynamometer including a steering angle detection mechanism detecting left steering angle information indicating a left tire turning angle that is an angle of the first-type left tire with respect to a reference direction, and detecting right steering angle information indicating a right tire turning angle that is an angle of the first-type right tire with respect to the reference direction,

• the method comprising the steps of:
• (X) executing a turning determination process of calculating turning radii for comparison based on the left steering angle information and the right steering angle information, and determining whether a driving state of the vehicle is a steering/turning state or a driving straight state, based on comparison results between the turning radii for comparison and a turning radius for determination;
• and
• (Y) executing a turning control process in turning determination of determining, through the step (X), that the driving state of the vehicle is the steering/turning state,
• the turning control process to be executed in the step (Y) and comprising the steps of:
• (a) calculating four steering/turning radii that are steering/turning radii of the four tires;
• (b) measuring four roller rotation speeds that are rotation speeds of the four rollers;
• (c) calculating four control target speeds that are control target speed of the four rollers, based on the four steering/turning radii and the four roller rotation speeds;
• and
• (d) outputting the four roller driving commands based on the four control target speeds.