Key benefits of the methodology of compensation

Electronic means susceptible to take into account the issue of mechanical components expansion exist on the market today. The addition of sensors fixed up to strategic locations of the machine allows either measure the expansion of some components or measure their temperature. The most prevalent is currently adding a sensor measuring the spindle nose stretching. This way gives incomplete information on the geometric drift between the tool and machined workpiece. Based on the measure of these sensors, the numerical control provides compensation which is actually partial and indirect, because it is impossible to directly measure the distance between the tool and the workpiece, which is the only distance that guarantee the accuracy of the part. In all existing methods, it does not deal with the source of thermal effects, but it is tried to measure the indirect effects that serve as a basis for compensation. The causal relationship between the source of thermal effects and geometric drifts is difficult to establish and de facto compensation is incomplete.

The original method proposed here avoids the using of sensors. It is why it is called "sensorless". It is based solely on a mathematical model of the machine, previously acquired as a result of relevant and appropriate measures of geometric drifts between the tool and the workpiece, during an identification phase. The product comes in the form of an algorithm implemented in the numerical control which is based on the history of how different actuators acted. The way of considering the main sources of thermal effects provides the adequate compensation of the consecutive geometric drifts.

The key benefits of the methodology allows a substantial improvement of the absolute accuracy and the repeatability of machines, this by controlling the distance between the tool and the workpiece. A crucial aspect for the manufacturer of the machine is that this objective is achieved without additional electronic means. What this translates into increased reliability and the economy of expensive components. These characteristics allocate a measurable competitive advantage to the manufacturer of machine.