My Research, a small R&D company from Lithuania, demonstrated a new method of remote vehicle control. The lead researcher, Aleksey Zaitsevsky, noted that humans control vehicles in a completely different way compared with automatic devices.
For instance, if a car is resting, the driver does not know by how many turns of the steering wheel the wheels are turned in either direction. When the car is moving, the driver also doesn’t know this angle, but will turn the wheel to make the actual trajectory match the desired imaginary one. If you release the wheel, it will automatically return to the neutral position. Unlike a real driver, automatic and remote control systems always monitor the status of the steering mechanism. The majority of standard servo drives come with an integrated position sensor. Controllers set the exact steering wheel turn angle. However, it turned out that steering wheel position control is not always necessary. More than that, in some cases, automation mechanisms offer more accurate driving along a set trajectory without analyzing the position of the steering wheel. The invention was demonstrated on radio-controlled plane and ship models. In these experiments, the steering wheel position sensor was replaced with a force sensor.
The essence of these modifications can be easily explained using another example. When a light piloted plane is on the ground, the steering wheel can be easily turned sideways, while the ailerons (air rudders on the wings) are in an arbitrary position. But when the air stream starts pushing on the rudders, they will assume the neutral position and so will the steering wheel. In order to turn the rudders, the pilot has to apply force to the steering wheel grip. The new type of servo drives does exactly the same and applies certain force, but does not control the exact position of the steering wheel. In order to control such a plane automatically, you only need to control the trajectory and apply force to rudders if the plane goes off course.
Replacement of the position sensor with a force sensor makes for safer remote control. The reason is that a regular servo drive turns rudders by a set angle at any speed. If the speed is too high, a sudden maneuver can topple over a motor boat or destroy a plane with extra-high Gs. But the higher the speed, the more pressure is applied to air rudders – and the force sensor detects it. The new mechanism with a force sensor turns rudders more at low speeds and less at higher speeds. Therefore, it guarantees the safety of maneuvering at high speeds and improved maneuverability at low speeds. Besides, the force sensor prevents the damage of the mechanism if the rudder is jammed for any reason.
Apart from various means of transportation, servo drives with a force sensor can be used in robotics – for instance, for gripping fragile items. The developer of the mechanism emphasize the possibility of using the new servo drive for automatic camera stabilization. If a video camera rests on an unstable platform, the electronics no longer need to know its exact tilt. The position of the camera is detected relative to the surrounding space and you don’t need to take platform swaying into account.
Project website: http://f-servo.com/