A method includes, when a handheld device is in motion within a service area to be traversed by a robot: obtaining ultra-wideband (UWB) ranging measurements between the handheld device and multiple anchors located in the service area; and obtaining image data and inertial measurement unit (IMU) data. The method also includes determining a trajectory of motion of the handheld device based on the UWB ranging measurements. The method also includes adjusting the trajectory based on image features obtained from the image data and motion estimates obtained from the IMU data. The method also includes identifying the adjusted trajectory as a boundary of the service area.