Soft robotic hydraulic log gripper system - SOFT LOGGING

Forests are the predominant land cover in the European Union, accounting for about 42%, and their area has increased by almost 10% in the last 20 years. Therefore, timber production is an important ecosystem service of European mountain forests. Modern technologies allow the extraction of logs in almost all terrain types, even in mountain areas that are difficult to access. However, not all technical equipment used for this purpose is available. Logging and forestry machines on the ground are the predominant technologies used in the Alpine region, in contrast to cable cranes, which are designed for very steep slopes or wet or fragile terrain, but involve much higher investment costs. In order to reduce the cost of forestry work, very productive machines such as harvesters and forwarders, operated by one person, are the ideal solution. The advantages of smaller forestry machines are lower investment and operating costs, as well as the possibility of multiple use and easy transportation. There are two main systems used for tractor towing, namely the rope system and the grapple system. Demographic change and an aging global population require new machines or assistance systems that relieve people of heavy physical labor in harsh environments, support increased productivity, and protect their health. The key to this vision lies in the implementation of more intuitive and easier as well as safer handling. The use of radio-controlled chokers in cable yarding can improve both productivity and safety during the unhooking of the logs. However, the system still requires manual adjustment of the choker, which added weight and labor. Compared to rigid grippers, soft grippers have a lower frictional force due to the lower normal interaction force, but a greater adhesion due to a larger contact area. Using gripping principles is a suitable way to automate the gripping process and increase efficiency and safety. The synthesis of new soft robots can also be adapted to classical methods already available in the field of mechanics. The flexibility of soft body parts can also be modulated by combining materials with different mechanical properties. When soft robotics are used for gripping, greater flexibility is provided in terms of shape, size, structure, safety, and control compared. To answer these key challenges of automatic and safe hooking and unhooking of the logs, as part of this project we will use soft robotics as new innovative approach for gripping different objects, of an arbitrary geometry, based on hydraulic actuator to increase actuator power. We will adjust and use the soft robotic gripper for handling heavy loads and will provide small, portable hydraulic power control unit for such system.  The main goal of this project is to design, build and test the world-first soft-robotic hydraulic device to for automatic hooking and unhooking of the logs. To achieve the overall goal we will analyze the mechanical behaviour of soft robotic materials and different shapes to ensure high gripping forces by performing numerical modelling and parametric optimization. This is followed by experimental verification to directly evaluate the holding force and characterize the most promising materials for soft robotics, as well as the design and testing of a high-load soft robotic hydraulic actuator. A self-powered high-pressure hydraulic device will be designed and tested to control the soft robotic actuator. Basic project requirements are: simple and reliable implementation at the end of the logging winch rope; secure hold of the log on the ground during logging, reliable unhooking of the log at the unloading site; possibility of separate or simultaneous unhooking of several logs attached to the steel cable of the forestry winch, all parts of the automatic hooking/unhooking device at the end of the winch rope must will be very light; the first load of the hydraulic device should be directly on the forestry winch.