To facilitate the manufacture of an accurate receiver, a piezoelectric device manufacturer determines characteristic data, such as an approximate expression representative of a temperature characteristic of piezoelectric device and coefficients of the approximate expression, and stores it to a memory of a manufacturer’s computer corresponding to a serial number of each piezoelectric device. A skid plate provides a surface on which a tongue of the towed item slides toward alignment over a hitch such as a hitch ball or pintle hook. The controller module may receive the balance signal from the balance control sensor and calculate a balancing velocity of the motorized omni-directional wheel based at least in part on the balance signal and an inverted pendulum control algorithm.