The KM-30S is a door control card developed to eliminate installation difficulties due to lack of available space, minimize inefficient space-use and control heavy/light doors slowly or rapidly in a reliable manner without any vibration.
One of the biggest advantages is that it is just 30 millimeters high. This way, it can be mounted just behind the door jamb. This saves space on the cabin. In addition, the necessity to change the door parameters on the cabin is removed.
The KM-30S was designed to EN 81-20 standard. To comply with the EN 81-20 standard, when the KM-30S detects an obstacle, it stops closing and opens. When the door needs to be closed again, it closes slowly from the point where the obstacle was detected. This way, problems arising from jamming and collision are prevented. In addition, the software limits the pressure to 150Nm as required by the EN 81-20 standard. Since pressure above this level may cause injuries, this potential problem is prevented.
The KM-30S also does not allow the control unit to move the cabin without making sure that the door is fully closed. For full compatibility with different control panels, it has dry contact relays which specify if “the door is fully opened,” “the door is fully closed,” or if “jamming has been detected.”
The KM-30S uses the “Smart Motor Control” method, which is one of today’s motor driving trends. “Standard Motor Control” is used in outdated technologies. The differences between these two methods are as follows: In Standard Motor Control, voltage and frequency are the basic control variables. Moment and flux are the components of these two variables.Because the speed control is performed by changing the V/Hz ratio in standard systems, the motor’s response to the applied PWM signals is connected to the weight (load) on the motor. The effect created by the moment and flux slows down the motor response. Due to this effect, control of motors using standard methods is limited. This limitation can be eliminated with vector controlled drives. Vector controlled drives use a much more effective motor driving technology. To ensure precise control, voltage and frequency interfere with the pulse-width modulation (PWM) signals in parallel with the target value. For a stronger, faster reaction, the voltage and frequency vectors must be calculated accurately. Microprocessors are used for this purpose. This allows the use of feedback information for ensuring the accuracy of the calculations. Vector control is performed with two systems: with sensor (closed loop) or without sensor (open loop). Sensor vector control, as the name implies, requires equipment forfeedback. In sensorless control, the AC driver follows the motor independently of the sensor and adjusts the voltage and frequency according to the current – torque character.
In contrast to the other door control cards, the KM-30S boasts two of the most distinctive features: door learning and motor recognition.
For motor recognition, information such as the user, motor current, pole number and gear ratio is confirmed in the menu. When the motor is run, the position and speed information of the door are also fed back via the encoder. With this feedback, discrepancies are detected and reported back to the motor. Therefore, the motor does not lose power. These features provide smooth transitions between the acceleration and deceleration curves in the ramp profiles. It also allows the door to open and close quickly, but smoothly. The door learning feature allows the user to connect the KM-30S to the door motor without any adjustment and activates the learning menu. The door limits are correctly set without limit switches and the door is now ready for use.
With the built-in temperature sensor, the motor energy is cut off in case of overheating to avert any potential danger.
In KM-30S, a Permanent Magnet Synchronous Motor (PMSM) was preferred. Nowadays, these motors have replaced the classic motors. They enable speed control at high intervals. Since they are brushless, they are smaller than DC motors. Another advantage of being brushless is that breakdowns are very rare and maintenance is easier. They can also be used with both low and high power. The Arkel KM-30S motor is designed specifically for the KM-30S and therefore works with high efficiency.
Mehmet Kurt Arkel R&D Hardware Design Specialist
In 2012, he graduated from the Department of Electronic Teaching at Gazi University. During his undergraduate education, he won 9th place with his team at the Robocon competition which was held in Thailand in 2010 with attendance of 19 countries. He won 5th place in the RobotChallenge competition held in Austria in 2011. In 2013, he started his first job as an Embedded System Design Engineer at a company that produces fire and gas detection systems. At the beginning of 2018, he started to work at Arkel as an R&D Hardware Specialist. As the project leader, he designed KM-30S. Together with the project management responsibility for KM-30S, he is currently leading two other projects.