Mobile carriage system with no rails for guidance system

A mobile storage system for use along a support surface devoid of any floor mounted guide rails, comprising:

• a plurality of mobile carriages each having a first side frame and a second side frame and extending laterally between a first end and a second end, each mobile carriage including a first drive motor positioned near the first end of the mobile carriage and a second drive motor positioned near the second end of the mobile carriage, each mobile carriage including a plurality of support wheels that support the carriage directly on the support surface;
• a control unit contained on each of the mobile carriages, wherein the control unit controls the operation of the first and second drive motors to selectively move the mobile carriage along the support surface;
• a guidance system in communication with the control unit, wherein the guidance system includes a magnetic strip mounted to the support surface, at least one magnetic sensor positioned on each of the mobile carriages and operable to detect the magnetic strip, a first distance sensor positioned at the first end of the mobile carriage and operable to detect a first distance from the first side frame to a stationary target and a second distance sensor positioned at the second end of the mobile carriage and operable to detect a second distance from the first side frame to the stationary target, wherein the control unit controls the operation of the first and second drive motors to maintain the position of the mobile carriage along the magnetic strip based on a detection signal from the magnetic sensor and to maintain the orientation of the first end and the second end of the carriage by maintaining the first and second distance equal to each other.

A guidance system for use in a mobile storage system having a plurality of mobile carriages that are each movable along a support surface through operation of a first drive motor and a second drive motor mounted to each of the movable carriages, the guidance system comprising:

• a magnetic strip mounted to the support surface to define a movement path for each of the mobile carriages;
• at least one magnetic sensor mounted to each of the movable carriages to detect the magnetic strip;
• a first distance sensor positioned at a first end of each mobile carriage and a second distance sensor positioned at a second end of each mobile carriage, wherein the first distance sensor is operable to detect a first distance from a first side frame of the mobile carriage to a stationary target and the second distance sensor is operable to detect a second distance from the first side frame to the stationary target;
• and a control unit coupled to the magnetic sensor and the first and second distance sensors, wherein the control unit operates the first and second drive motors to move the carriage along the movement path, and wherein the control unit operates the first and second drive motors based upon distance measurements from the first and second distance sensors to maintain the first and second distances equal to each other.