Information on inclination and acceleration can mean the difference between success and (possibly critical) failure in mobile machinery. Smart Inertial Measurement Units provide the data necessary to improve process efficiency and ensure safety.
In mobile machinery with outriggers, unforeseen tipping and the subsequent loss of control is one of the greatest dangers for people and machine. If people are directly involved in the work process, such as with turntable ladders or jibs with baskets, the risk to life and limb is very clear. This makes it all the more important that the position of the extendable equipment is safely captured and monitored. The automation and sensor specialists at STW in Kaufbeuren have developed the 6-axis IMU SMX.igs-a for this purpose. The inertial measurement unit (IMU) records accelerations, inclination angles and rotation rates in all three spatial axes to enable the machine or machine part to be precisely monitored.
The SMX.igs-a is available in safety variants certified to SIL2 / PL d,suitable for applications with special functional safety requirements, such as the examples already mentioned that have direct human involvement.
Smart support system
A non-safety version of the sensor is available for less critical applications. It is characterized by the inclusion of a Kalman filter. This merges the acceleration and rotation rate data using sensor data fusion. It is a filter algorithm that calculates the measured values, predicts the further course and corrects the values accordingly. The Kalman filter is characterized by high dynamics and yet very good damping. With position and acceleration projection, great efficiency gains can be realized. In braking systems, for example, the braking pressure can be regulated using the slope or gradient information during the descent. This protects machine components and helps the machine operator.
Andreas Huster, Head of Sensors & Measuring Systems at STW, emphasizes: ‘The trend towards driver assistance and the conservation of resources has long since arrived in mobile machinery. Our SMX.igs-a can make a valuable contribution here’. Automated assistance systems help reduce stress on both operator and investment intensive machinery.
Another application example of the SMX.igs-a is automated boom levelling and positioning for excavators. It enables the machine operator to make repeatable machine movements and create slopes or particularly level surfaces more precisely.
Easy to integrate
In addition to the integrated intelligence of the sensor, the measuring system is characterized by its user-friendly integration. A new, compact cast housing with two M12 connections was developed for the SMX.igs-a. The sensor housing is only 2.5 cm high and has a width and depth of just over 7 cm. This means that it can be integrated into even the most confined installation spaces. With no separate supply cable on the sensor, machine manufacturers have greater flexibility to decide how and where they want to install the SMX.igs-a. With protection classes up to IPX9K and an operating temperature range between -40°C and +85°C, the IMU is suitable for the most adverse operating conditions, from mining to agricultural to forestry machinery. There are no limits to the sensor's applications.
The smart sensor is of course not only mechanically integrated into the machine design, but also into the automation and control architecture. The software integration is particularly user-friendly thanks to the support of STW’s open-source software platform openSYDE. Configuration dashboards simplify initial set up and parameterization of the sensor, both for newly designed systems and for retrofit. During development and commissioning the measured values can be intuitively visualized via the CAN monitor.
Dirk Hübner, Head of Product and Project Management at STW Chemnitz, adds: ‘With the newly developed IMU, machine manufacturers can design even smarter, more efficient and safer machines. With the extensive software support, we make it particularly easy for our customers' engineering teams. We are looking forward to the OEMs‘ ideas for further applications of the SMX.igs-a.’
The SMX platform from STW, which also includes the SMX.dms-a strain transducers, can also be used as a basis for the development of condition monitoring systems. In cooperation with the machine manufacturer, the sensor experts at STW can realize unique custom solutions for specialized applications.
STW will be displaying the SMX products at Sensor+Test in Nuremberg, 11-13 June in Hall 1, Stand 508.