# Motion Generation for Crane Simulators Using Streamlined Motion Blending Technology
## 1 Introduction  
Driven by the trend of the continuous penetration of unmanned intelligent control technology into almost all industrial sectors, the idea of unmanned fully automatic container quasayide container crane has also been suggested for many years. However, due to technical difficulties, there is still no sign that the unmanned container crane can be put into practical use in a short period of time [1]. At present, in the actual container terminals, the traditional manually operated quasayide cranes still account for the vast majority of the total. According to the survey data obtained from Ningbo port in China, about 75% of the quayside cranes in service are still manually operated. For these manually operated quasayide cranes, one of the most challenging problems is how to train novice operators to successively take over from the retiring workers. Using crane simulators to train new crane operators has proved to be a very effective method in that it has the advantages of saving cost, improving safety, not occupying the real equipment in service, not being restricted by adverse environmental conditions, and so on [2]. The quayside container crane simulator has appeared for many years, and its performance has been greatly improved through the continuous efforts of a large numberof scholars. The early research mainly focused on how to model the real-time dynamics of the related components and the assemblies of the crane manipulated by the trainees in the virtual space, especially to detect the possible collision in real time so that the best visual effect is achieved through the rendering process of the visual system in order to provide the operator with a highly realistic real-time dynamic immersion [1, 3, 4]. Another significant research problem that researchers focus on is how to design the simulator system architecture and quickly integrate together all the components involved in the entire virtual simulation system [5, 6, 7] including the motion platform [8, 9, 10]. Although the motion platform is considered to be an important part of the crane simulator, profound research is very lacking, and it is often regarded as a supplementary part of the system architecture design of the whole simulation system. [PERSON] et al. studied the functional and structural design of the motion platform in the quayside container crane simulator and discussed the motion generation algorithm for providing the motion perception through the motion platform as well as the software implementation [9]. The motion generation algorithm in this case is nevertheless a straightforward application of the traditional motion cueing algorithm including a washout process, which was originally and has now been widely used in vehicle simulators. Transplanting the motion cueing algorithm [11, 12, 13, 14, 15, 16, 17] on the vehicle simulator to the motion platform of a crane simulator [18, 19, 20, 21, 22, 23] can indeed solve some of the problems that will be encountered in the implementation of the system, but it is not the whole problem or even the main problem of crane motion perception simulation. In fact, for the crane simulator, this problem is not prominent as there are only a very few parts of the movements resulted from low-frequency continuous acceleration and continuous deceleration, for which the traditional washout algorithm is most effective to prevent the motion platform from exceeding its working space range when reproducing the motion in reality. The real difficulty of crane motion perception simulation is how to obtain a suit of suitable and easy-to-handle motion equations to reflect the current simulation conditions and parameterized user demands and then generate an equivalent motion on the platform with almost the same motion perception. Furthermore, the motion generation approach needs to be optimized by comprehensively considering the motion perception characteristics of the crane. Recently, [PERSON] et al.