Engine

An engine in which intake air guided by one intake path is distributed to cylinders, and exhaust gas collected from the cylinders is discharged through one exhaust path, comprising:

• a variable series supercharging system comprising a high-pressure supercharger and a low-pressure supercharger each comprising a turbine rotated by receiving the exhaust gas flowing in the exhaust path and a compressor driven by the turbine so as to compress the intake air flowing in the intake path;
• a supercharging pressure sensor configured to detect a pressure of the intake air compressed by the variable series supercharging system;
• a high-pressure supercharger rotation sensor configured to detect a high-pressure supercharger rotation speed of the high-pressure supercharger;
• a high-pressure supercharger variable actuator configured to control a capacity of the high-pressure supercharger;
• and
• a control device configured to calculate a target high-pressure supercharger rotation speed and a target pressure of the intake air compressed by the variable series supercharging system, the control device being configured to control the high-pressure supercharger variable actuator based on the detected pressure of the intake air compressed by the variable series supercharging system, the detected high-pressure supercharger rotation speed of the high-pressure supercharger, the target high-pressure supercharger rotation speed, and the target pressure of the intake air compressed by the variable series supercharging system.