Control device for vehicular lamp and vehicle lighting system

A control device for a vehicular lamp which variably controls optical axis of the vehicular lamp in accordance with an attitude change in the pitch direction of a vehicle comprising:

• an angle calculation part,
• wherein the angle calculation part obtains acceleration values each associated with the vertical direction and the horizontal direction of the vehicle at a predetermined time interval, and obtains a first acceleration value related to the vertical direction of the vehicle and a second acceleration value related to the horizontal direction of the vehicle by eliminating gravitational acceleration component from each of the acceleration values,
• wherein the angle calculation part calculates a vehicle traveling direction acceleration based on the first acceleration value and the second acceleration value, and further obtains an attitude angle of the vehicle based on a correlation between either one of the first acceleration value or the second acceleration value and the vehicle traveling direction acceleration, and
• an optical axis setting part which generates a control signal for controlling the optical axis of the vehicular lamp based on the attitude angle of the vehicle obtained by the angle calculation part, and provides the control signal to the vehicular lamp.