01-08-2010, 10:13 AM
The Navbelt
The Navbelt consists of a belt, a portable computer, and an array of ultrasonic sensors mounted on the front of the belt. In the experimental prototype shown in Figure 3 the user wears a fanny pack on the abdomen and a portable computer as a backpack. Eight ultrasonic sensors, each covering a sector of 15° are mounted on the front pack, providing a total scan range of 120°.
The computer processes the signals that arrive from the sensors, and applies the robotics obstacle avoidance algorithms described in Section 2. One fundamental difference between the OAS implemented on a robot and on the Navbelt is illustrated in Figure 4: The electrical guidance signals, which originally controlled the steering and drive motors of the robot (see Figure 4a) are replaced by acoustic signals that are relayed to the user by stereophonic headphones (see Figure 4b).
A binaural feedback system based on internal time difference (i.e., the phase difference between the left and right ear) and amplitude difference (i.e., the difference in amplitude between the two ears) creates a virtual direction (i.e., an impression of directionality of virtual sound sources). The binaural feedback system is used differently in each of the three operating modes that are described next.
The Navbelt consists of a belt, a portable computer, and an array of ultrasonic sensors mounted on the front of the belt. In the experimental prototype shown in Figure 3 the user wears a fanny pack on the abdomen and a portable computer as a backpack. Eight ultrasonic sensors, each covering a sector of 15° are mounted on the front pack, providing a total scan range of 120°.
The computer processes the signals that arrive from the sensors, and applies the robotics obstacle avoidance algorithms described in Section 2. One fundamental difference between the OAS implemented on a robot and on the Navbelt is illustrated in Figure 4: The electrical guidance signals, which originally controlled the steering and drive motors of the robot (see Figure 4a) are replaced by acoustic signals that are relayed to the user by stereophonic headphones (see Figure 4b).
A binaural feedback system based on internal time difference (i.e., the phase difference between the left and right ear) and amplitude difference (i.e., the difference in amplitude between the two ears) creates a virtual direction (i.e., an impression of directionality of virtual sound sources). The binaural feedback system is used differently in each of the three operating modes that are described next.
