Ultrasonic press using servo motor with delayed motion

An ultrasonic welding system comprising:

• an ultrasonic welding stack movable, in response to control inputs, to initiate a welding operation by applying vibrational energy to a workpiece;
• a plurality of sensors to measure respective control variables, the plurality of sensors outputting control signals corresponding, respectively, to the control variables;
• and
• a motion control system coupled to and causing controlled movement of the ultrasonic welding stack, including the initiation of the welding operation, the motion control system
• determining, based on the control signals received from the plurality of sensors, the control inputs such that any motion of the ultrasonic welding stack, subsequent to initiating the welding operation, is initially delayed until the control signals indicate that the control variables satisfy a predetermined condition associated with sensed parameters of the plurality of sensors, and
• causing the ultrasonic welding stack to move, in response to the predetermined condition being satisfied, in accordance with a weld profile.