Simulated collaboration of multiple controllers

A simulation method comprising:

• executing a first simulation of a first control of a first machine, wherein the first control is executed by a first controller;
• executing a second simulation of a second control of a second machine, wherein the second control is executed by a second controller so that the second machine operates in collaboration with the first machine;
• and
• controlling progress of the first simulation and progress of the second simulation to maintain a simulated ratio of a progress speed of the first simulation and a progress speed of the second simulation to be equal to a ratio of a progress speed of the first control and a progress speed of the second control,
• wherein the first control includes a first set of cycles and the first controller is configured to execute each of the first set of cycles after a first control period,
• wherein the second control includes a second set of cycles and the second controller is configured to execute each of the second set of cycles after a second control period, and
• wherein said controlling the progress of the first simulation and the progress of the second simulation includes:
• counting a number of simulation cycles;
• selecting the first simulation in response to determining that the number of simulation cycles becomes a number corresponding to the first control period;
• selecting the second simulation in response to determining that the number of simulation cycles becomes a number corresponding to the second control period;
• executing one of the first set of cycles in response to a selection of the first simulation;
• and
• executing one of the second set of cycles in response to a selection of the second simulation.

A simulation device comprising circuitry configured to:

• execute a first simulation of a first control of a first machine, wherein the first control is executed by a first controller;
• execute a second simulation of a second control of a second machine, wherein the second control is executed by a second controller so that the second machine operates in collaboration with the first machine;
• control progress of the first simulation and progress of the second simulation to maintain a simulated ratio of a progress speed of the first simulation and a progress speed of the second simulation to be equal to a ratio of a progress speed of the first control and a progress speed of the second control;
• and
• change the progress speed of the first simulation and the progress speed of the second simulation in response to a designation of playback speed.