Automatic dual flush activation

A system for controlling the flush volume of a flushometer, comprising:

• a dual flush valve associated with a waste receptacle fixture, the dual flush valve having a solid waste flush volume corresponding to a full flush volume and a liquid waste flush volume corresponding to a reduced flush volume;
• a presence detection sensor associated with the flush valve, the presence detection sensor configured to monitor for the presence of a user and provide a signal upon the detection of a user in a predefined area;
• an automatic flush control in communication with the presence detection sensor and the dual flush valve, the automatic flush control comprising a memory unit associated with the presence detection sensor and the flush valve, the memory unit having stored therein computer program instructions for:
• receiving the presence detection sensor signal;
• initiating a usage timer upon the detection of the user;
• stopping the usage timer upon no longer receiving a presence detection sensor signal;
• generating a usage time tx that equals time elapsed from initiation to stoppage of the usage timer when the user is no longer detected;
• modifying a usage cycle count Nc by increasing Nc by 1;
• determining if a number of cycles Nc is less than a predetermined number of cycles Np,;
• if Nc<Np,
• then determining if the usage time tx is greater than or equal to a preset usage time value Tp where if tx is greater than or equal to the preset value Tp, then the flush valve is opened for the full volume flush, and if tx is less than the preset value Tp, then the flush valve is opened for the reduced volume flush;
• if Nc>Np,
• then determining if the usage time tx is greater than or equal to a calculated average usage time tp where if tx is greater than or equal to the calculated average usage time tp, then a full volume flush is performed, and if tx is less than the predetermined average usage time tp, then the reduced volume flush is performed;
• and
• modifying tp according to the value of tx,
• wherein the automatic flush control provides instructions actuating the dual flush valve for the solid waste flush volume or the liquid waste volume based on usage time.