Fuel gas supply control device, fuel gas supply control method, and method of starting fuel-cell vehicle

A fuel gas supply control device comprising:

• a fuel gas supply device that includes an electric valve that is electrically opened and shut off, the fuel gas supply device being configured to supply a fuel gas to a fuel gas consuming device configured to consume the fuel gas when the electric valve is open;
• a fuel gas sensor that has a predetermined unstable period until an accuracy of fuel gas detection reaches a predetermined level after the fuel gas sensor has been supplied with an electric power;
• and
• a control unit configured to
• (i) cause the electric power to be supplied to the fuel gas sensor and open the electric valve when starting of the fuel gas consuming device is instructed,
• (ii) determine a temporary abnormality of the fuel gas sensor and shut off the electric valve to temporarily stop the supply of the fuel gas to the fuel gas consuming device when a signal input from the fuel gas sensor is greater than a predetermined determination threshold value before the predetermined unstable period elapses and
• (iii) cancel the determination of the temporary abnormality and open the electric valve when the signal from the fuel gas sensor is not greater than the predetermined determination threshold value in a predetermined period after the electric valve has been shut off.