What kind of accuracy can be achieved for camera stabilization?
What are the reasons behind camera tilting?
On possible horizontal deviations of the camcorder.
A question about the work of the device in windy conditions.
What kind of servo should be used in the gimbal?
How to configure gyroscopes on the Ecilop mount?
Why do you use separate gyroscopes instead of a single block of three-axis stabilization?
How to configure PID in the flight controller?
Is it possible to allow two persons to control the drone and the camera on it independently?
Can the size of Ecilop Easy be reduced for easy transportation by plane?
Will a drone with eight rotors be more reliable than a quad-copter?
Can I use your technology for building my own drone?
Question: what kind of accuracy can be achieved for camera stabilization?
Answer: Stabilization on a regular servo gear works in the following way: a) an unwanted tilt takes place; b) electronics measure the tilt value; c) the servo gear compensates the tilt. Ecilop is not just about stabilization, it's about initial camera stability plus tilt control. An usual direct servo-gear has measurable side play and it seriously affects the image quality (usual gimbal). In case of Ecilop's inertial stabilization, you cannot specify an exact discrete value. Ecilop offers a very high level of angular camera stabilization. This is the type of stabilization that provides the highest image quality. The camera may tilt, but it happens smoothly.
Flying controller is responsible for the camera tilt and compensation of hull tilt. Direct servo translates twitching into camera. Bad mount with direct gear drive causes strong twitching; expensive mount - less twitching and more delays due to additional reduction gear. Gimbal with direct brushless drive provides smooth rotation but is heavy, weak and uses lots of energy. Inertial stabilization is needed to eliminate twitching. For inertial stabilization to work properly hard link between gimbal and frame must be eliminated. System with springs automatically turn into balance wheel that swings. To avoid swinging on the Ecilop signal from flight controller to the servo is translated through gyroscope.
What are the reasons behind camera tilting?
If camera tilting is permanent, it may be caused by the following reasons:
1. The center of mass of the mount does not match the center of rotation in the horizontal plane - you need to balance this.
2. The servo-gear is not configured correctly - set an exact value for the neutral position.
3. Once of the springs is overstretched - replace the springs.
4. The cables are pulling the unit aside - make sure that cables bend easier and are properly fastened.
If camera tilting is occasional, this may be caused by the following:
1. The center of mass of the mount does not match the center of rotation in the vertical plane - you need to balance this.
2. The cables are too rigid - make sure that cables bend easier.
3. The controller creates redundant counter-tilting when neutralizing natural in-flight tilting - adjust the proportion of anti-tilting in the controller.
4. The controller tilts the camera during or after a maneuver - use a smoother piloting style, as the controller's accelerometers detect the gravity vector incorrectly.
5. Wind gusts tilt the camera - it is recommended that the camera and counterweight be approximately of the same shape and mass.
On possible horizontal deviations of the camcorder.
The camera may tilt during maneuvers and after them. This happends because onboard controlers use accelerometers for finding the horizon. However, gravitation, centrifugal force and inertia are indiscernible for an accelerometer. This cannot be compensated with an electronic gyroscope, since the speed and turn radius are unknown. If you keep flying in circles or slow down after a turn, the camera may tilt following an erroneous command of a controller. When flying along an arc trajectory or with a linear acceleration, an effect of artificial gravity is created. An optical horizon sensor does not have this problem, but has a number of other drawbacks.
Some flight controllers are operating with a delay. The signal delay may be caused by the noise removal algorithm. Noise removal makes the motion of the camera smoother, but causes delays. Because of noises, the camera may get jerky on a direct servo gear. In case of Ecilop, a slightly noisy signal is better than a delayed one. On Ecilop, slight vibrations of the servo gear are not a big problem, since they are compensated for by inertia.
A question about the work of the device in windy conditions.
I will split this question into two parts each addressing a separate subject: 1 - the behavior of the camera; 2 - the behavior of the quadcopter itself.
1. Camera. In Ecilop Easy, the areas of the battery and the camera, as well as their distance from the center of rotation are about the same. It means that the pressure of the wind is uniform. If you install a heavy camera closer to another drone's center of rotation, and leave the battery in its initial position, a gust of wind may result in a smooth and relatively small swerve. The battery is too heavy to work as a sail. The multicopter flies at a speed of 20 m/sec and the air flow does not cause considerable wandering. Unlike the manual Steadicam, Ecilop features gyroscopes that prevent swaying. Therefore, a small imbalance of mass or wind pressure may result in slight deviation from the course, but no swaying will take place.
2. Quadcopter. The engine and engine rest of Ecilop Easy, which has a total weight of 2.2 kg, weigh less than a kilogram. This allows the engine to react to tilt commands just as quickly as on lighter drones. This means that the drone is more sensitive to flight normalization commands in windy conditions.
What kind of servo should be used in the gimbal?
We recommend using fast servos with a minimal "dead zone". If a servo has a large "dead zone", small-range camera swaying will not be stopped by gyro. The power of the servo should be proportional to the stretching force of the spring. For the Ecilop Easy it must be 2 kg/cm or more (springs are included). The better the mechanism is balanced, the weaker the springs can be. The heavier the mechanism is and the harder it is to rotate it, the stronger the springs should be. If weak springs are used, the effect of inertial stabilization is higher, but the amplitude of random fluctuations is also higher. Stronger springs reduce the amplitude of random fluctuations, but movements become less smooth.
How to configure gyroscopes on the Ecilop mount?
As gyroscope is responsible only for swinging avoidance, it can be adjusted without flying controller by giving signal directly from receiver.
Adjustable parameters of gyroscope:
If gyroscope is not weakening but straightening the swinging - reverse to be turned on;
Delay parameter - minimum;
Limitation of the servo motion - maximal motion with no limits;
Exponents and proportions - not to be used;
Reaction speed - maximal;
Servo type - establish according to the factual;
Work mode - necessarily "Rate" or "Normal"
Adjustment of gain rate is as follows:
Start with maximal reaction rate. If mechanism starts to tremble when gimbal is not moving then lower the reaction rate. Push the gimbal with You finger – it has to move back smoothly to its place with no swinging. If swinging appears than gyroscope reaction is insufficient, increase the gyroscope gain value. If during maximal gain rate swinging is noticeable following may help: use faster servo with minimal dead band, use more tight springs, use another gyroscope.When the equipment is turned on, the gimbal must be stable, otherwise the gyroscopes will be initialized incorrectly and the camera will be tilted. If the onboard controller generates a high-frequency PWM signal, some simple gyroscopes may not work.
Why do you use separate gyroscopes instead of a single block of three-axis stabilization?
A three-axis block has a fixed position relative to the third axis. The tilt of the sensors changes relative to the two other axes. A three-axis block calculates acceleration as a sum of cosines and sines from different sensors. Proportionality in the measurements of different sensors can be high, but not ideal. Errors often occur due to non-linearity in measurements. An error is when a tilt in one plane causes a reaction of a servo mechanism in another one. Example: if a single block is tilted forward at an angle of 50 degrees, there is no more gyroscope that would measure the sideward tilt directly.
If you are using the simplest gyroscopes, but they work independently for each axis, this error won't occur.
* An electronic camera stabilizer is often referred to as inertial stabilization. Such controllers have integrated inertial sensors. These sensors allow the controllers to calculate the necessary tilt value. The camera position is set by a servo-gear triggered by a certain control command. However, this is electronic, rather than inertial, stabilization. When inertial stabilization is used, a servo-gear is only used for trimming the camera position. Some examples of pure inertial stabilization are a heavy mechanical gyroscope or a balance beam.
How to configure PID in the flight controller?
In most situations, factory settings need not to be changed. Accurate adjustment is performed in the same way it is done on other drones. However, there is one more simple, yet somewhat dangerous, configuration method:
Disable the servo-units controlling the camera. For personal safety, put on some clothes made of dense and strong fabric. Hold the drone with one hand by the battery and lift it. Start the engines and adjust the thrust so that it can keep the drone aloft. Change the values of the function and watch the behavior of the drone.
Is it possible to allow two persons to control the drone and the camera on it independently?
You can use video goggles with a built-in head tracker. In this case, the camera operator uses the goggles for controlling the camera tilt and turning the drone, while the pilot controls its position. For the same purpose, you can connect two remote controls in the student/instructor mode. If necessary, the pilot can always switch all controls over to his remote.
Can the size of Ecilop Easy be reduced for easy transportation by plane?
The frame of the drone is not foldable, but compact. You can carry both a drone and a remote control unit in one hand. The drone occupies just one car seat and is always ready to fly. Engine rigger and the chassis are assembled using screws. You can unscrew them to fit the entire drone into a travel bag (12 screws).
Will a drone with eight rotors be more reliable than a quad-copter?
Additional rotors increase the reliability and the price of a drone. In most situations, drones crash because of the pilot's mistake. The number two reason is carelessness and lack of attention during drone assembly and pre-flight preparation. The more bolts and wires a drone has, the higher is the chance of one of them falling out or going off. People who use drones for work strive to minimize inevitable damage after crashes and simplify maintenance. Today, a classic helicopter with a single high-quality rigid rotor is a more reliable option than a multi-copter with light propellers. A simple multi-copter is just a more cost-efficient solution for simple tasks. Ecilop Easy is a quadcopter with a simple design, since simplicity is a precursor of reliability. Where possible, the design uses rivets instead of screws - and that's how aeronautical and space equipment is assembled. If a rivet has to be removed, it's drilled through, removed and replaced with a new one.
Can I use your technology for building my own drone?
Ecilop drones use a patented camera stabilization technology. If you copy this principle of camera stabilization, each technical or marketing text related to your product(s) must mention the name of the technology's author and an active link to ecilop.com (Camera rotation control by Aleksey Zaitsevsky, ecilop.com ).
A short history of a "Steadi":
Couter-balanced camera mount was invented in 1931, Patent US2007215
Steadicam - a human body supported mount, first patent US4017168
Skycam - a cable supported mount, first patent US4625938
Ecilop - camera rotation control (soft connection with a servo plus a gyroscope), first patent LT5816.
Thank you for your interest in my products.
* Please don't send general inquiries by email. You will find answers to most questions on the RCGroups forum.
Comparison of modern technologies (direct drive vs Ecilop):
