Design of an Automated Multiposition Dynamic Wheelchair

This work presents a design for an automatized multiposition dynamic wheelchair used to transport quadriplegic patients by reconfiguring a manual wheelchair structure. An electric actuator is attached to a four-bar mechanism fixed to each side of a wheelchair’s backrest to reach multiposition. The entire device is actuated through a PID controller. An experimental test is carried out in a simplified wheelchair structure. Finally, the structure of the wheelchair is evaluated through the Dynamic analysis and Finite Element Method under the payload computed with the most critical position reached by the mechanism.

Cost Effective, Digital, Fail-Safe Production Tree and Wellhead Actuator System

E&P companies are challenged with the cost-effective development of smaller and marginal fields, while ensuring safety for its crew and facing increasing regulatory requirements for further reducing emissions and environmental impact. Key enablers to achieve profitable development of smaller fields and maintaining safe production in remote locations is digitizing and automating the production chain and limit the need for on-site personnel. There are a number of safety critical valves on wellheads and production trees that have historically been manually or hydraulically operated and thus not suited for fully remote operations. In 2017, Equinor, Baker Hughes and TECHNI formed a Joint Industry Project (JIP) to develop a new electric actuator control system. The actuator system is designed for fail-safe, critical operations offshore and is subject to stringent safety design requirements. The key driver is reducing CAPEX and OPEX and environmental impact for offshore installations, while increasing availability of wells while providing improved monitoring and condition based, predictive maintenance. The electric actuator system developed in the JIP has a patent pending fail-safe mechanism with extremely fast closing time to ensure well containment during critical situations. It is designed to be a drop-in replacement for existing hydraulic actuator solutions and is suitable for most standard wellhead and tree designs, sizes, and pressure ratings. The all-electric solution contains a multitude of sensors, that, in combination with an integrated digital interface, enables data-driven insights from the systems in operation. The actuator development is currently at Technology Readiness Level (TRL) 4 on the API 17N, 0 to 7 scale. In 2020, the JIP consortium was awarded NOK 8.2 million (USD 950 000) by the Norwegian Research Council DEMO 2000 program to support the test and qualification program. TRL 5 testing is planned in first half of 2021 yielding it ready for field installation.

Rams Analysis for Different XT Technologies

This paper analyses the probability of failure on demand of different subsea christmas tree actuation principles and their related control system architectures. The all-electric technology has limited or insufficient field data available. This means that the reliability and availability analysis is based on theoretical analysis from data provided in reliability handbooks for mechanical and electronic components. The analysis includes the probability of failure on demand to isolate the well and the availability of each equipment type until a first failure causes the need for repair. The following different actuator and system designs were chosen for this analysis: – Spring based hydraulic actuator – Spring based electric actuator – Electric power screw actuator – Electric planetary roller screw actuator All Electric Systems (except the spring based electric actuator) utilize a battery to provide the energy for the valve operation. The reliability analysis provides detailed information about the major contributors that limit the reliability of the actuators and systems. With this knowledge, qualification activities can focus on the improvement of the reliability of the critical components and the actuator elements within the system. The power screw actuator and the corresponding system provides the best reliability and availability compared to other systems. The electric with spring design provides better results than the hydraulic with spring design. Generally, the battery-based systems provide a better reliability than spring-based designs. The most critical elements are the mechanical springs, sealings, brakes and the spindle mechanisms. Another aspect is the analysis of an optimized operation strategy in order to utilize the redundant components to improve the availability and reduce the number of interventions by analysis of the second and third failure in the system.

Condition Monitoring of Next Generation Digitized Electric Subsea Actuators

A detailed knowledge about the health status of the installed assets is the key for continuous production without unexpected events and downtime, which causes production loss. A major aspect is the prediction of the occurrence of a failure before the affected function is demanded. This is one purpose of the Condition Monitoring (CM), Prognostics and Health Management (PHM) and the application of a Digital Twin. The paper presents the result of an ability analysis for a subsea actuator towards its possibilities to increase the availability through a novel and extensive grade of information. The paper presents the resulting architecture and solution to achieve an actuator design, which is capable to provide a high safety, high reliability and a predictive health management which is prepared for a digital twin application. For this purpose, an applied Condition Monitoring concept is described and shown based on the case study. The analysis and resulting solution is based on a detailed research towards the state of the art. Different available subsea actuators are analyzed towards the communication interfaces and the ability to allow CM. Therefore, the required status and information of the actuator are shown (e.g. Torque, position, temperature, acceleration, water concentration in oil, humidity, pressure, inclinometer). The required environment information about the actuator are evaluated with the help of a failure mode analysis. The different sensor principles provide the necessary information. The paper evaluates the significance of the sensor information towards the CM concept. The data can be provided on different communication interfaces and protocols. These are analyzed towards the satisfaction of the CM requirements. The result of the analysis is a detailed architecture of a CM capable subsea electric actuator including the CM concept. The possible interfaces are shown and the provided sensor data by the actuator. The sensors provide the input for the CM model and the remote accessibility and controllability of the actuator. The result is the novel design of a subsea actuator, which fits perfect in a digitalized subsea environment to increase the availability and controllability including a CM concept.

A Novel Subsea Actuator to Electrify Small-Bore Valve

This paper presents the development and qualification of a novel Subsea Electric Actuator, especially designed for rotary small-bore valves. One of the main challenges was to design an electric actuator which is as compact as the existing hydraulic actuators, but able to provide a fail-safe mechanism by field-proven springs and full integration of all necessary components, including the electric drive and controls, inside of a compact enclosure. Furthermore, the design team had to considerably reduce its power consumption and weight in comparison to existing solutions. Finally, the system was designed for lean manufacturing, allowing considerable cost-saving benefits for all the partners due to extensive standardization work. The paper shows the engineering requirements obtained by interviewing different users, the design methodology applied and the qualification of the new system up to TRL 3 with Digital Twin and Rapid Prototyping. Finally, an outlook is presented with the planned TRL 4 and TRL 5 qualification tests and a summary of the technical and economic benefits for the users of this novel Subsea Valve Actuator.