CpiV1(double sigma_w, double sigma_wb, double sigma_a, double sigma_ab, bool imu_avg_=false)
Default constructor for our Model 1 preintegration (piecewise constant measurement assumption)
void feed_IMU(double t_0, double t_1, Eigen::Matrix< double, 3, 1 > w_m_0, Eigen::Matrix< double, 3, 1 > a_m_0, Eigen::Matrix< double, 3, 1 > w_m_1=Eigen::Matrix< double, 3, 1 >::Zero(), Eigen::Matrix< double, 3, 1 > a_m_1=Eigen::Matrix< double, 3, 1 >::Zero())
Our precompound function for Model 1.