Lunar explorations have provided us with information about its abundant resources that can be utilized in orbiting-resource depots as lunar-derived commodities. To reduce the energy requirements of a launcher to send these commodities from the lunar surface to the space depots, this paper explores the application of the electromagnetic acceleration principle and provides an assessment of the actual technical characteristics of the launcher’s installation to ensure the acceleration of a payload with a mass of 1,500 kg to a speed of 2,200 m/s (circumlunar orbit speed). To fulfill a lightweight (fewer materials and less energy) support structure for the electromagnetic launcher with strength requirements, the tensegrity structure minimum mass principle without global buckling has been developed and applied to support the electromagnetic acceleration device. Therefore, this paper proposes and develops a minimal mass electromagnetic tensegrity lunar launcher. We first demonstrate the mechanics of launcher and payload, how a payload can be accelerated to a specific velocity, and how a payload carrier can be recycled for another launch. Then, a detailed discussion on the lunar launch system, procedures of propulsion, the required mass, and energy of the launch barrel are given. The governing equations of tensegrity minimal mass tensegrity design algorithm with gravity and without global buckling. Finally, a case study is conducted to show a feasible structure design, the required mass, and energy. The principles developed in this paper are also applicable to the rocket launch system, space elevator, space train transportation, interstellar payload package delivery, etc.

This paper introduces a data-driven approach to address the long-standing challenge of modeling complex tensegrity systems. The proposed approach focuses on approximating unknown black box systems and estimating their output error covariance using input/output (IO) information. First, an approximation system that mirrors the input–output relation of the black box system is obtained. Next, output error covariance between the approximation and the black box system is calculated, which evaluates the accuracy of the identified model. This two-step approach relies exclusively on the black box system’s Markov parameter sequence, eliminating the need for dynamics knowledge of the system. Nonlinear examples of a NACA 2412 tensegrity morphing airfoil and a 3D tensegrity prism are studied for validation. The proposed approach successfully identified approximation systems in state space realization in both cases with insignificant output error covariances. Compared to the widely-used Mode Displacement Method (MDM), the proposed approach exhibits an advantage in identifying velocity outputs for tensegrity systems. The developed approach in this paper applies to other tensegrity structures and structural identification problems.

This paper introduces the concept of Pulley-Driven Clustered Tensegrity Structures (PD-CTS) and derives the governing equations of nonlinear and linearized statics and dynamics equations through the use of the Lagrangian method. The generalized coordinates used in the formulation are the nodal coordinates of the tensegrity structure and the sliding distances of the strings. The equations are presented in a clear and explicit form, taking into account both cases with and without boundary constraints. The proposed method can be applied to the nonlinear and linearized statics and dynamics analysis of any PD-CTS, covering a wide range of studies, such as loading analysis, form-finding, large deformation analysis, modal analysis, and dynamic response under various input. The substructure method is used to reduce the order of the equations, saving computational costs and allowing for the study of the actuation strategy of tensegrity structures. The efficiency of the proposed approaches is demonstrated through the examination of two examples: a 2-dimensional T-bar and a 3-dimensional tensegrity tower. The methods developed in this paper can also be used to study deployable cable net structures and pulley-driven robots.

This study introduces an integrated approach that merges the design of structure and control to study the deployment strategies for tensegrity structures, particularly in the context of space antennas. First, we establish a nonlinear shape control law for clustered tensegrity structures, the solution turns out to solve a constraint linear algebra equation. Leveraging the symmetric nature of the antenna structure, we designate active actuators for the top and bottom cables of the space antenna while considering the remaining cables as passive. To further reduce the number of actuators required, we employ various clustering strategies for the active actuating cables. Results show that the deployment from the initial state to the predetermined targets is successfully guided by the proposed control law through clustering active cables using different actuation strategies. It is significant to note, however, that the energy cost escalates as more cables are clustered into the deployable antenna structures. In the context of space applications, this scenario emphasizes structure design and control are not independent problems. These insights also offer extensive relevance and can be extrapolated to different deployable tensegrity structures and robotic systems.

Drilling operations are increasingly becoming a manufacturing process where repeatability, versatility, and speed matter the most for an operator or future space missions. Nonetheless, the ongoing energy transition efforts will undoubtedly shape the objectives and priorities of drilling operators into new markets with unexplored technical challenges. Versatility, mobility, and automated systems will play crucial roles in determining successful applications. This study explores and introduces the application of tensegrity-based structures, commonly used in space exploration, to Earth and Space drilling systems by modeling, designing, and building a tensegrity-based miniature drilling rig. Robust models for designing a drilling rig based on tensegrity structures and anticipated load conditions are presented. In addition, the drilling tests and experimental results described proving that the tensegrity could be applied to unusual applications such as drilling. The lightweight tensegrity-based structure is feasible for drilling applications on Earth and Mars by tuning design variables such as structure complexity, bar and string sizes, pre-stress, Etc. Tensegrity structures allow more volume-efficient, lightweight, and deployable mechanisms essential for space deployment. It also enhances rig mobility, reducing drilling costs and the environmental footprint of the Earth based-system by downsizing the site's carbon expenditure.

Drilling and Extraction Automated System (DREAMS) is a fully automated prototype-drilling rig that can drill, extract water and assess subsurface density profiles from simulated lunar and Martian subsurface ice. DREAMS system is developed by the Texas A&M drilling automation team and composed of four main components: 1- tensegrity rig structure, 2- drilling system, 3- water extracting and heating system, and 4- electronic hardware, controls, and machine algorithm. The vertical and rotational movements are controlled by using an Acme rod, stepper, and rotary motor. DREAMS is a unique system and different from other systems presented before in the NASA Rascal-Al competition because 1- It uses the tensegrity structure concept to decrease the system weight, improve mobility, and easier installation in space. 2- It cuts rock layers by using a short bit length connected to drill pipes. This drilling methodology is expected to drill hundreds and thousands of meters below the moon and Martian surfaces without any anticipated problems (not only 1 m.). 3- Drilling, heating, and extraction systems are integrated into one system that can work simultaneously or individually to save time and cost.

This study presents the design and analysis of deployable cable domes based on the clustered tensegrity structures (CTS). In this paper, the statics and dynamics equations of the CTS are first given. Using a traditional Levy cable dome as an example, we show the approach to modify the Levy dome to a deployable CTS one. The strings to be clustered are determined by the requirement of prestress mode and global stability. The deployment trajectory is proposed by changing the deployment ratio (the ratio between the radius of the inner and outer rings of the cable dome). Then, the quasi-static and dynamic deployment of clustered tensegrity dome is studied. Results show that the proposed CTS cable dome always has one prestress mode and is globally stable in its deployment trajectory. In the deployment process analysis, the dynamics show that the system's dynamic response differs from the quasi-static simulation as the actuation speed increases. That is, for a fast deployment process, quasi-static simulation is not accurate enough. The dynamics effects of the deployment must be considered. The developed approaches can also be used for the design and analysis of various kinds of CTS.

—This paper develops a systematic data-based approach to the closed-loop feedback control of high-dimensional robotic systems using only partial state observation. We first develop a model-free generalization of the iterative Linear Quadratic Regulator (iLQR) to partially-observed systems us-ing an Autoregressive–moving-average (ARMA) model, that is generated using only the input-output data. The ARMA model results in an information state , which has dimension less than or equal to the underlying actual state dimension. This open-loop trajectory optimization solution is then used to design a local feedback control law, and the composite law then provides a solution to the partially observed feedback design problem. The efficacy of the developed method is shown by controlling complex high dimensional nonlinear robotic systems in the presence of model and sensing uncertainty and for which analytical models are either unavailable or inaccurate.

This paper proposes a model-based approach to control the shape of a tensegrity system by driving its node position locations. The nonlinear dynamics of the tensegrity system is used to regulate position, velocity, and acceleration to the specified reference trajectory. State feedback control design is used to obtain the solution for the control variable as a linear programming problem. Shape control for the gyroscopic tensegrity systems is discussed, and it is observed that these systems increase the reachable space for the structure by providing independent control over certain rotational degrees of freedom. Disturbance rejection of the tensegrity system is further studied in the paper. A methodology to calculate the control gains to bound the errors for five different types of problems is provided. The formulation uses a Linear Matrix Inequality (LMI) approach to stipulate the desired performance bounds on the error for $\mathcal{H}_\infty$, generalized $\mathcal{H}_2$, LQR, covariance control and stabilizing control problem. A high degree of freedom tensegrity $T_2D_1$ robotic arm is used as an example to show the efficacy of the formulation.

Stems of land plants provide mechanical support and long-distance transport of water and carbohydrates. Although it has long been recognized that plant stems can also store water, it remains uncertain what role stem water plays in mitigating drought stress and maintaining whole plant function ([

In tensegrity, axially loaded 1-D members are methodically arranged to obtain an optimal structural response. These structures were inspired by Kenneth Snelson, who, as an artist, created topologies of this sort. The energy storage properties of a tensegrity topology known as the D-bar are determined analytically in this work. Such energy storage properties are compared against those of bent buckled beams, which have been proposed as components for mechanical energy absorption in planetary landers. An example comparing the energy storage capabilities of a tensegrity lander vehicle with D-bar structures against those of a vehicle with bent buckled beams is also presented. It is shown that D-bar structures of low complexity have higher energy storage and lower mass than bent beams; analogous results are determined in the example of the tensegrity lander. These results imply that D-bar structures can significantly enhance the response of planetary landers as well as other applications such as seismic-resistant buildings and micro-structured materials that would benefit from low-mass/high-energy absorption parts.

Tensegrity system dynamics is a subset of the class of multi-body dynamics which includes cylindrical rigid bodies (bars) and elastic members (strings) arranged in a stabilizable topology (Skelton & Oliveira, 2009). Tensegrity structures appeared in earlier artworks by Karl Ioganson in 1921 and Kenneth Snelson in 1948 (Sultan, 2009). The term tensegrity was first coined by Buckminster Fuller (1959), and is a portmanteau of “tensional integrity” and Snelson (1965) filed the first patents on this topic. Tensegrity structures are created by methodically arranging tensile members (strings) and compressive members (bars) to form a stable system. Skelton & Oliveira (2009) define a tensegrity structure as a “class-1” tensegrity system if none of the compressive members are connected, if, on the other hand, k compressive members are connected at a node, this is referred to as a “class-k” tensegrity system. The multiple compressive members are connected through ball joints, causing all the members in a tensegrity structure to be axially loaded, i.e., no moment is present on any individual member. Tensegrity structures can also be prestressed to have uni-directional loading for all the individual members giving the freedom to design tension and compression members separately. This freedom provides good structural efficiency (high strength-to-mass ratio) to tensegrity structures. A particular topology of tensegrity structure can provide various self-equilibrium solutions corresponding to different values of prestress in the structure. The various stable prestress values provide a domain set to minimize the mass of the structure. This minimization has proved tensegrity to be an optimal mass solution for various loading conditions (Skelton & Oliveira, 2009). Moreover, different prestress values correspond to different stiffness, allowing one to change the stiffness without changing the shape. These properties of tensegrity structure have led researchers to use tensegrity concepts in various applications from civil engineering bridges (Carpentieri, Skelton, & Fraternali, 2015) to soft-robotics (Karnan, Goyal, Majji, Skelton, & Singla, 2017; Sabelhaus, Akella, Ahmad, & SunSpiral, 2017) to various space applications; landers (Goyal et al., 2019; SunSpiral et al., 2013), deployable structures (Tibert & Pellegrino, 2003), and, space habitat designs (Goyal, Bryant, Majji, Skelton, & Longman, 2017).

A tensegrity structure involves the presence of elements withstanding pure compression, and others under pure tension only. Metal rubber is introduced into a tensegrity prism strut to create a mechanical metamaterial with energy absorption and tuneable dynamic properties. In this work we describe the design and development of the meta-tensegrity structure with particular emphasis on the evaluation of parameters such as the structural size, the metal rubber stiffness, the initial internal force and the external compression load. Prototypes of tensegrity prisms with and without metal rubber inserts have been assembled and subjected to quasi-static loading. The model used to design the meta tensegrity prism has been then modified to take into account specific manufacturing and internal dissipation mechanisms typical of this configuration. The updated model provides a better comparison with the experimental results. Both the theoretical and experimental data show that the introduction of the metal rubber within the tensegrity configuration contributes to improve significantly the energy absorption, and to reduce the stiffness of the whole tensegrity structure.

This paper describes the nonlinear dynamics of planar tensegrity bridges designed for minimal mass. The three-dimensional bridge benefits by the planar analysis in the most important manner relating to topology of material. We start with the minimal mass bridge, counting both structural mass and deck mass, and then derive the nonlinear dynamics to study dynamic behavior of the minimal mass bridge. Suggested design criteria include static and dynamic response. The minimal mass tensegrity has an optimal complexity (number of elements), and we show how the dynamic response influences the best choice of complexity, in comparison with the optimal complexity of the static design. The structures are first designed with minimal mass criteria, accounting for equilibrium and static stability conditions

This paper produces a design for a minimal mass, deployable support structure for a solar panel covering of water canals. The results are based upon the minimal mass properties of tensegrity structures. The efficient structure is a tensegrity system which has an optimal complexity (i.e. an optimal number of members) for minimal mass. This optimal complexity is derived in this paper, along with deployable schemes which are useful for construction, repairs, for Sun following, and for servicing. It is shown that the minimal structure naturally has deployable features so that extra mass is not needed to add the multifunctional features. The design of bridge structures with tensegrity architecture will show an optimal complexity depending only on material choices and external loads. The minimization problem considers a distributed load (from weight of solar panels and wind loads), subject to buckling and yielding constraints. The result is shown to be a Class 1 Tensegrity substructure (support structure only below the deck). These structures, composed of axially-loaded members (tension and compressive elements), can be easily deployable and have many port-able applications for small spans. The focus of this paper is an application of these minimal mass tensegrity concepts to design shading devices to prevent or reduce evaporation loss, while generating electric power with solar panels as the cover. While the economics of the proposed designs are far from finalized, this paper shows a technical solution that uses the smallest material resources, and shows the technical feasibility of the concept.

Recent studies have investigated the use of tensegrity structures for the construction of active solar façades of Energy Efficient Buildings (EEBs).The present work moves along such lines by proposing a methodology that supports the development of the design and construction process of new façade components with tensegrity architecture.The activation motion of the examined tensegrity façade system mimics the dynamics a blinking sail.The use of the proposed façade system as a dynamic sun-screen or a wind-energy harvesting device is presented, with the aim of illustrating the application of tensegrity architectures to the design of next-generation dynamic solar façades of EEBs.

This paper will show that a simple membrane (e.g. balloon) is not always the minimal mass pressure vessel. Of course one could always add cables to support the membrane, or plate, to reduce the thickness and hence mass required of the membrane. By minimizing the sum of the mass of the membrane plus the mass of the cable network, a minimal mass solution for the pressure vessel can be found. We will show the necessary and sufficient conditions (involving material choices and cable network topology) for which a.composite system, composed of a membrane and cable network, has less mass than a membrane alone. The main motivator for this study is a spin-stabilized pressurized space structure useful for artificial gravity habitats.To contain and support the membrane, we will optimize the topology of the class of prestressable structures called tensegrity. These structures are usually composed of a network of axially-loaded compressive and tensile members. In the pressurized examples of this paper, inflation provides the compressive forces, and hence the optimized tensegrity topology eliminates the compressive structures when they are not needed. The minimal mass designs herein produce easily-tunable prestressed networks, and control systems that allow deployment and stiffness tuning features.The minimal mass design of those structures, for different load combinations (pressure loads and centrifugal loads), produces a composite structure composed of membranes and cable network. Two different composite systems are analyzed and compared with simple uniform membranes: the first system is composed of a cylindrical membrane supported by circular ring cables, the second system is composed by a membrane surrounded by ring cables and longitudinal cables. The comparison of the minimal mass designs with the single continuous membrane clearly highlights the advantage of the composite systems made of high-performance materials. When the material of the membrane and cables are the same, there is no advantage to the composite system, but various requirements usually demand different properties of the membrane and cable material. (C) 2016 Elsevier Ltd. All rights reserved.