There are many interesting topics to be studied with the rowing robot. For example, there is evidence that oars as propelling devices are more energy efficient than a propeller when the speed is moderate under the displacement velocity. Power output of an average human rower is only 100-150 W and with a standard small rowing boat a speed around 2 m/s (3,5-4 kn) can be obtained. The same speed to power ratio is hard to obtain with any small outboard motors.
Roboticed rowing offers interesting possibilities to recover old rowing boat cultures, like multi-oar Viking boats or big fishing boats, by assembling several rowing robots on a same boat.
The test vehicle, shown in the picture, is a 4,0 m small standard rowing boat. Weight without rowing mechanics, motors, batteries and control hardware is about 70 kg. The total weight with all equipment is 210 kg. The payload is still more than one person and the boat moves then with quite a small propulsion force like 30-50N on calm water level below the displacement velocity, which is about 1.9 m/s (3,7 kn). The propulsion system of the rowing boat consists of two degree of freedom oars. Total length of the oar is about 2.20 m, but the length outside the brink is 1,79 m. The rowing robot is equipped with two 100 AH batteries, which give power for rowing several hours. The oar motion is powered by two electric motors with gears. The nominal power of the main motor is 250 W with a reduction 92,70:1 and the lifting motor 70 W with a reduction 216:1.
Control hardware consists of four servo cards and an industrial PC/386
equipped with an IO-card. Position of the oar is measured by potentiometers.
The user interface is made up of commercial monitor, keyboard and
joystick. At the present state of development the user controls the boat
by the aid of one joystick by which he gives target values for the velocity
and heading of the boat. The fixed parameters of the oar working cycle
can be changed via keyboard. Some of the parameters are changed automatically
with the target values for the velocity and/or heading.
First outdoor tests 29.5.98