Abstract: A controller design for a dual input single output (DISO) system is applied to a robot for printing layouts at construction sites. The differential drive robot has a separately controlled linear actuator that moves the print head perpendicularly to the fore-aft axis of the robot. The output is the lateral position of the print head; the sum of the position of the linear actuator (faster stage) relative to a reference point on the front of the robot, which is determined by the steering of the robot (slower stage). Both are measurable. The controller coordinates the action of the separately controlled linear actuator and the differential steering to achieve fast convergence and sub-millimeter tracking. Simulations and experimental results demonstrate the effectiveness of the approach.

Abstract: Apparatuses, systems, and methods for controlling the position of the interface between two or more laminar flow stream in a microfluidic device. In one embodiment, an apparatus includes a first fluid reservoir shaving an output, a first pressure sensor connected to the output of the first fluid reservoir, a first actuator connected to the first fluid reservoir, a feedback loop connected between the first pressure sensor and the first actuator, a second fluid reservoir having an output, a second pressure sensor connected to the output of the second fluid reservoir, a second actuator connected to the second fluid reservoir, a feedback loop connected between the second pressure sensor and the second actuator, and a microfluidic device including a first input connected to the output of the first fluid reservoir, a second input connected to the output of the second fluid reservoir, and an output.