Full Vehicle Simulation of Forwarder With Semi-Active Suspension Using Co-Simulation

Author(s):  
Robert Braun ◽  
Liselott Ericson ◽  
Petter Krus

A major concern in the forest industry is impact on the soil caused by forest machines during harvesting. A six-wheel pendulum arm forwarder is being developed. The new forwarder aims at reducing soil damage by an even pressure distribution and smooth torque control and thereby also improving the working environment. The suspension contains pendulum arms on each wheel controlled by a hydraulic load sensing system in combination with accumulator. A natural approach is to model each part of a system in the best-suited software. In this case, the hydraulic system is modelled in the Hopsan simulation tool, while the vehicle mechanics is modelled in Adams. To understand the whole system it is necessary to simulate all subsystems together. An open standard for this is the Functional Mock-up Interface. This makes it possible to investigate the interaction between the hydraulic system and the multi-body mechanic model. This paper describes how different simulation tools can be combined to support the development process. The technique is applied to the forwarder’s pendulum suspension. Controllers for height and soil force are optimized to minimize soil damage and maximize comfort for the operator.

2015 ◽  
Vol 8 (1) ◽  
pp. 2005-2009
Author(s):  
Diandong Ren ◽  
Lance M. Leslie ◽  
Congbin Fu

 Legged locomotion of robots has advantages in reducing payload in contexts such as travel over deserts or in planet surfaces. A recent study (Li et al. 2013) partially addresses this issue by examining legged locomotion over granular media (GM). However, they miss one extremely significant fact. When the robot’s wheels (legs) run over GM, the granules are set into motion. Hence, unlike the study of Li et al. (2013), the viscosity of the GM must be included to simulate the kinematic energy loss in striking and passing through the GM. Here the locomotion in their experiments is re-examined using an advanced Navier-Stokes framework with a parameterized granular viscosity. It is found that the performance efficiency of a robot, measured by the maximum speed attainable, follows a six-parameter sigmoid curve when plotted against rotating frequency. A correct scaling for the turning point of the sigmoid curve involves the footprint size, rotation frequency and weight of the robot. Our proposed granular response to a load, or the ‘influencing domain’ concept points out that there is no hydrostatic balance within granular material. The balance is a synergic action of multi-body solids. A solid (of whatever density) may stay in equilibrium at an arbitrary depth inside the GM. It is shown that there exists only a minimum set-in depth and there is no maximum or optimal depth. The set-in depth of a moving robot is a combination of its weight, footprint, thrusting/stroking frequency, surface property of the legs against GM with which it has direct contact, and internal mechanical properties of the GM. If the vehicle’s working environment is known, the wheel-granular interaction and the granular mechanical properties can be grouped together. The unitless combination of the other three can form invariants to scale the performance of various designs of wheels/legs. Wider wheel/leg widths increase the maximum achievable speed if all other parameters are unchanged.


2012 ◽  
Vol 468-471 ◽  
pp. 1266-1269
Author(s):  
Yan Jun Zhang ◽  
Zi Ming Kou ◽  
Gui Jun Gao ◽  
Jun Zhang

Abstract. To improve the automation degree in special working environment which contains explosive gas. We develop a new type of temperature control hydraulic sensor basically on theory and lots of experiments. As the temperature reaches about 85°C,the motion part of the inductor will stretch to a certain length, and then it will push the adjusting rod. Simultaneously,the adjusting rod will overcome the elastic force of the spring and compel the spool valve to deform, and finally the control valve port will be open, it allows the control oil of the hydraulic system to pass. At last it reaches our destination that we can make the control of hydraulic circuit be realized.


2013 ◽  
Vol 418 ◽  
pp. 63-69
Author(s):  
Sema Patchim ◽  
Watcharin Po-Ngaen

In last decade, energy efficiency of hydraulic actuators systems has been especially important in industrial machinery applications [1-. And an advanced electronics world most of the applications are developed by microcontroller based embedded system. Energy processor based variable oil flow of hydraulic controller was presented to improve the efficiency of the motor by maintaining with the load sensing. These PIC processor combined with fuzzy controller were help to design efficient optimal power hydraulic machine controller. A functional design of processor and in this system was completed by using load sensing signal to control oil flow. The advantage of the proposed system was optimized operational performance and low power utility. Without having the architectural concept of any motor we can control it by using this method. This is a low cost low power controller and easy to use. The experiment results verified its validity.


2013 ◽  
Vol 655-657 ◽  
pp. 1456-1459
Author(s):  
Li Ping Xu ◽  
Chen Fei Zhan ◽  
De Zhi Ren

Because ordinary hydraulic system exists multiple fault, power waste and hard controlling in actuators due to the complexity of actuators and variability of load. A new hydraulic system based on the load sensing technology is designed for the new type steel arch installing machine. The results of the simulation for forearm loop based on AMESim show that the designed hydraulic system is energy-efficient and load sensing function is effectively achieved, the actuator control performance is well.


2021 ◽  
Vol 868 (1) ◽  
pp. 012038
Author(s):  
S M Mirzaliev ◽  
M K Sultonov ◽  
G Lucci ◽  
A K Igamberdiyev ◽  
N А Kholikova

Author(s):  
Zhihui Li ◽  
Yaoxing Shang ◽  
Zongxia Jiao ◽  
Shuai Wu ◽  
Jianyong Yao

Electro-hydraulic load simulator (EHLS) is a typical closed-loop torque control system. It is used to simulate the load of aircraft actuator on ground hardware-in-the-loop simulation and experiments. In general, EHLS is fixed with actuator shaft together. Thus, the movement of actuator has interference torque named the surplus torque on the EHLS. The surplus torque is not only related to the velocity of the actuator movement, but also related to the frequency of actuator movement. Especially when the model of the actuator and EHLS is dissimilar, the surplus torque is obviously different on different frequencies. In order to eliminate the surplus torque for accurate load simulation, the actuator velocity input feedforword compensating method (AVIFC) is proposed in this paper. In this strategy, the actuator velocity synchronous signals are used for compensation of different frequency actuator movement to eliminate surplus torque on different frequencies. First, the mathematical model of EHLS and the actuator system is established. Based on the models, the AVIFC method is proposed. It reveals the reason that generates surplus torque on different frequencies of actuator. For verification, simulations and experiments are conducted to prove that the new strategy performs well against low, medium, and high frequency movement interference. The results show that this method can effectively suppress the surplus torque with different frequencies and improve precision of EHLS with actuator movement.


Author(s):  
Matthias Liermann ◽  
Christian Feller ◽  
Florian Lindinger ◽  
Dirk Runge

Abstract The paper presents a HiL test setup for hydraulic propel systems that includes a multi-body dynamic simulation of a vehicle in a realistic 3D environment. It allows testing of driving scenarios under load conditions that would otherwise be very difficult to obtain. The hydraulic-mechanical part of the simulation is modeled in Simulink. An open-source C++ physics engine is used to model the vehicle multi-body mechanics and collision detection between the vehicle and the 3D environment. Despite the high complexity of the hydraulic drive train component models, the constraint of real-time execution of the simulation on a real-time target can be fulfilled.


Author(s):  
André R. Roy ◽  
Scott J. Beatty ◽  
Virag Mishra ◽  
Dean M. Steinke ◽  
Ryan S. Nicoll ◽  
...  

Ocean industries such as oil and gas, defence, and marine renewables, face the challenge of costly and risky deployments and operations due to their complex and capital intensive nature. Numerical simulation tools are valuable assets that can be used to anticipate motions and stresses and therefore inform structural and operational design before deployment. Simulation tools that can capture all pertinent hydrodynamic phenomena increase their value by reducing design time, uncertainty, risk and capital associated with a deployment. Validation of numerical tools is critical to ensure accuracy and reliability. The following paper reviews a framework for simulation of moored, multi-body, floating systems, including the component models employed, the results of a model verification study, and the challenges encountered in the project. Tank test data of a moored horizontal cylinder was provided for the purposes of numerical tool validation.


Author(s):  
D T Branson ◽  
P S Keogh ◽  
D G Tilley

This paper addresses a controller design methodology for the hydraulic actuation of non-linear multi-body systems. It takes account of system uncertainties, envisaged system changes through added mass, positioning speed requirements, and vibration control. A mathematical model developed in the companion paper, Part 1, describes an experimental multi-body structure that is actuated by a hydraulic system. It is used to generate H∞-based position and active vibration controllers to meet the actuation requirements at the design stage. Experimental tests were undertaken with the developed H∞ controllers to demonstrate their accuracy and stability of motion control. The results are compared to ‘base level’ tests completed using a more traditional proportional-integral (PI) controller. In contrast with the instability experienced using PI control, the design process associated with the H∞ controllers ensures accurate closed loop stability over the range of system variations.


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