Conceptual Design and Analysis of Four Types of Variable Stiffness Actuators Based on Spring Pretension

Guo, Jishu; Tian, Guangdong

doi:10.5772/60580

Cited by 9 publications

(3 citation statements)

References 21 publications

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“…Therefore, the stiffness can be properly controlled to reduce energy requirements during the execution of repetitive tasks, as explained in Reference [40]. Reviews on variable stiffness actuators can be found in References [41][42][43][44], whereas a comparison of several design of VSA based on spring pretension is illustrated in Reference [45].…”

Section: Serial Compliance Elementsmentioning

confidence: 99%

Natural Motion for Energy Saving in Robotic and Mechatronic Systems

et al. 2019

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Energy saving in robotic and mechatronic systems is becoming an evermore important topic in both industry and academia. One strategy to reduce the energy consumption, especially for cyclic tasks, is exploiting natural motion. We define natural motion as the system response caused by the conversion of potential elastic energy into kinetic energy. This motion can be both a forced response assisted by a motor or a free response. The application of the natural motion concepts allows for energy saving in tasks characterized by repetitive or cyclic motion. This review paper proposes a classification of several approaches to natural motion, starting from the compliant elements and the actuators needed for its implementation. Then several approaches to natural motion are discussed based on the trajectory followed by the system, providing useful information to the researchers dealing with natural motion.

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Section: Serial Compliance Elementsmentioning

confidence: 99%

Natural Motion for Energy Saving in Robotic and Mechatronic Systems

et al. 2019

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“…Another study [17] reported a VSA created only from linear springs; whereas Guo et al [18] proposed four types of VSAs based on spring pretension with use of many parallel springs set at different angles. With this system, variable stiffness is achieved by adjusting the end points of the springs.…”

Section: Variable Stiffness and Impedance Actuatorsmentioning

confidence: 99%

Low power consumption mini rotary actuator with SMA wires

Manfredi

Huan

Cuschieri

2017

Smart Mater. Struct.

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Shape memory alloys (SMAs) are smart materials widely used as actuators for their high power to weight ratio despite their well-known low energy efficiency and limited mechanical bandwidth. For robotic applications, SMAs exhibit limitations due to high power consumption and limited stroke, varying from 4% to 7% of the total length. Hysteresis, during the contraction and extension cycle, requires a complex control algorithm. On the positive side, the small size and low weight are eminently suited for the design of mini actuators for robotic platforms. This paper describes the design and construction of a light weight and low power consuming mini rotary actuator with on-board contact-less position and force sensors. The design is specifically intended to reduce (i) energy consumption, (ii) dimensions of the sensory system, and (iii) provide a simple control without any need for SMA characterisation. The torque produced is controlled by on-board force sensors. Experiments were performed to investigate the energy consumption and performance (step and sinusoidal angle profiles with a frequency varying from 0.5 to 10 Hz and maximal amplitude of ). We describe a transient capacitor effect related to the SMA wires during the sinusoidal profile when the active SMA wire is powered and the antagonist one switched-off, resulting in a transient current time varying from 300 to 400 ms.

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“…Therefore, the flexible joint based on a variable stiffness actuator is considered an important strategy, becoming the focus of the relevant research. The variable stiffness actuators include linear [7][8][9] and rotational [10,11]. Linear actuators are usually applied for the knee joint, legged robotics, and finger joints.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Design and Experiments of a New Rotational Variable Stiffness Actuator for Hybrid Passive–Active Stiffness Regulation

Wang,

Gao,

Wang

et al. 2023

Actuators

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To improve collision safety in robot–human collaborative applications, increasing attention has been paid to rotational variable stiffness actuators. A new rotational variable stiffness actuator, which works in two stages, is proposed for hybrid passive–active stiffness regulation. The passive stage is based on the motions of springs driven by the rack-and-pinion systems, elastically converting the shaft’s rotation into the inner shell rotation fixed to the internal gear of the active stage. The active stage is designed to achieve the movement of the pivot point located on the roller actuated by the adjustment motor, providing the output angle of the output shaft. The two pairs of rack-and-pinion systems of the passive stage and the two pairs of planetary gears of the active stage are designed for side-by-side placement, improving the stability and balance of the stiffness regulation process. Two symmetrical cam-slider mechanisms acting as leverage pivots ensure the synchronous movements of the two rollers. The variable stiffness actuator is designed and validated by simulations and experiments. Strength analysis and stiffness analysis are presented. The designed actuator can obtain the range of stiffness adjustment of 35–3286 N·mm/deg. The range of the angle difference between the input and output shafts is ±48°.

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Conceptual Design and Analysis of Four Types of Variable Stiffness Actuators Based on Spring Pretension

Cited by 9 publications

References 21 publications

Natural Motion for Energy Saving in Robotic and Mechatronic Systems

Natural Motion for Energy Saving in Robotic and Mechatronic Systems

Low power consumption mini rotary actuator with SMA wires

Mechanical Design and Experiments of a New Rotational Variable Stiffness Actuator for Hybrid Passive–Active Stiffness Regulation

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