Systems and methods are provided for verifying the placement of tows by a robot. One embodiment includes a robot that includes an end effector that lays up tows, actuators that reposition the end effector, a memory storing a Numerical Control (NC) program, and a robot controller that directs the actuators to reposition the end effector based on the NC program, and instructs the end effector to lay up tows based on the NC program. The system also includes a sensor system comprising an imaging device that acquires images of the tows as the tows are laid-up, a measuring device that generates input as tows are laid-up by the end effector, and a sensor controller that receives images from the imaging device and the input from the measuring device, and updates stored data to correlate the images with instructions in the NC program, based on the input.