  Cooking robots have long been desired by the commercial market, while the
technical challenge is still significant. A major difficulty comes from the
demand of perceiving and handling liquid with different properties. This paper
presents a robot system that mixes batter and makes pancakes out of it, where
understanding and handling the viscous liquid is an essential component. The
system integrates Haptic Sensing and control algorithms to autonomously stir
flour and water to achieve the desired batter uniformity, estimate the batter's
properties such as the water-flour ratio and liquid level, as well as perform
precise manipulations to pour the batter into any specified shape. Experimental
results show the system's capability to always produce batter of desired
uniformity, estimate water-flour ratio and liquid level precisely, and
accurately pour it into complex shapes. This research showcases the potential
for robots to assist in kitchens and step towards commercial culinary
automation.
