<p>The purpose of this thesis was to investigate different methods do measure velocity of pistons in pneumatic cylinders at Bosch Rexroth Teknik AB. Through information of velocity the adjustment of a cylinders damping can be done easier.</p><p>A future transducer will be used by salesmen, service personnel and customers. This requires a sensor that is easy to apply and use. It is also desirable that the sensor is cheap. A number of possible methods to measure velocity have been presented. In general, the requirements above have been difficult to fulfill.</p><p>In almost all pneumatic cylinders, magnets are mounted on the piston. Magnetic sensors are then used for proximity sensing to detect its extreme positions. A similar way can be used for velocity sensing. Assume that two magnetic sensors are placed on a fixed distance between each other, along the pistons direction of motion. The time to travel between the sensors is an expression for the velocity of the piston.</p><p>One way to solve the problem has been chosen and the accuracy of this method has been verified. This has been done under the assumption that the errors due to mounting is neglected and that the direction of sensitivity is idealistic.</p>

The purpose of this thesis was to investigate different methods do measure velocity of pistons in pneumatic cylinders at Bosch Rexroth Teknik AB. Through information of velocity the adjustment of a cylinders damping can be done easier. A future transducer will be used by salesmen, service personnel and customers. This requires a sensor that is easy to apply and use. It is also desirable that the sensor is cheap. A number of possible methods to measure velocity have been presented. In general, the requirements above have been difficult to fulfill. In almost all pneumatic cylinders, magnets are mounted on the piston. Magnetic sensors are then used for proximity sensing to detect its extreme positions. A similar way can be used for velocity sensing. Assume that two magnetic sensors are placed on a fixed distance between each other, along the pistons direction of motion. The time to travel between the sensors is an expression for the velocity of the piston. One way to solve the problem has been chosen and the accuracy of this method has been verified. This has been done under the assumption that the errors due to mounting is neglected and that the direction of sensitivity is idealistic.

Sedan urminnes tid har folk sysslat med mätning av olika slag. Tid, längd, höjd, area, energi, volym och styrka är några exempel på vad som behövde mättas. Att mäta är att jämföra verklighet med en fördefinierad enhet. En sekund, en meter, ett watt är några exempel på enheter som brukas för att kunna definiera en mätning. I dagens samhälle är det viktigt med exakt mätning för att kunna till exempel producera rätt tjänst i rätt tid, just in time, för att kunna utnyttja sina resurser effektivt. Detta innebär högre förtjänst med minimal insats, vilket gagnar både producent och konsument som använder denna tjänst. / Since time immemorial, people have been involved with the measurement of various kinds. Time, length, height, area, energy, volume and strength are some examples of what needed to be saturated. To measure is to compare the reality with a predefined unit.  One second, one meter, a watt is a few examples of devices that used to define a measurement. In today's society, it is important to have accurate measurements to be able, for example, produce the right services at the right time, just in time, to utilize their resources effectively. This means higher profits with minimal effort, which will benefit both producers and consumers who use this service.