An apparatus for performing driving aid control to cause a travel trajectory of a mobile object to follow a setpoint trajectory (La) by transmitting a control command value (δ) to a yaw moment controller capable of controlling a yaw moment of the mobile object. In the apparatus, a setpoint trajectory setter is configured to set the setpoint trajectory (La) of the mobile object. A control command value calculator is configured to calculate the control command value (δ) based on an integrated value (δI) of a lateral error that is an error between a position of the mobile object and the setpoint trajectory. The control command value calculator is further configured to decrease the integrated value (δI) with decreasing a curvature (ρ) of a road on which the mobile object is traveling.