The SPARKy (Spring Ankle with Regenerative kinetics) project: Choosing a DC motor based actuation method

Holgate, Matthew; Hitt, Joseph K.; Bellman, Ryan; Sugar, Thomas G.; Hollander, Kevin W.

doi:10.1109/biorob.2008.4762888

Cited by 43 publications

(28 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some authors also consider electrical power consumption by introducing a DC motor efficiency model. Typically, the model includes resistive losses [9,10] and sometimes losses proportional to motor speed [11,12]. In those papers which utilize a DC motor model, inertia of the motor is usually included, but gearbox inertia is rarely taken into account [9].…”

Section: Introductionmentioning

confidence: 99%

Modeling and design of geared DC motors for energy efficiency: Comparison between theory and experiments

et al. 2015

View full text Add to dashboard Cite

a b s t r a c tEnergy efficiency is a growing concern in today's mechatronic designs. In recent years, many works have emerged presenting energy-efficient actuators with electrical motors. However, there is little consistency in the way energy consumption is calculated. Drive inertia, motor efficiency and controller efficiency are often neglected in optimizations, and so are the load-and speed-dependency of the losses and other non-linearities. While this approach works well in stationary circumstances, it can lead to significant errors in highly dynamic tasks with a wide range of operation, such as the ones faced by actuators in the field of robotics. This paper discusses the losses occurring in an actuator consisting of a DC motor and gearbox as it is forcing a swinging motion on a pendulum. From this simple case study, some general recommendations on the modeling of energy losses are formulated. Combining data from manufacturer's datasheets with empirical data, the approach presented in this paper was able to predict the energy consumption for this specific case with an error of less than 10%.

show abstract

Section: Introductionmentioning

confidence: 99%

Modeling and design of geared DC motors for energy efficiency: Comparison between theory and experiments

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The best device in this category is the SPARKy 2 prototype [55,57,58] which has shown to support these 3 tasks. Other devices have the potential to be highly adaptable but still need to prove it.…”

Section: Comparison Analysis Of Propulsive Bionic Feet and Their Prefmentioning

confidence: 99%

“…At the Arizona State University (ASU-United States), the SPARKy project (Spring Ankle with Regenerative Kinetics) [55] uses a robotic tendon actuator (including a 150 W Brushed DC motor-Maxon RE40) [56] to provide 100% of the push-off power required for walking while maintaining intact gait kinematics. The first prototype (SPARKy 1 shown in Figure 10(a)) [57] was shown to store and release approximately 16 J of energy per step, while an intact ankle of a 80 kg subject at 0.8 Hz walking rate needs approximately 36 J [58]. A second prototype (SPARKy 2- Figure 10(b)) was built with a lighter and more powerful roller screw transmission and brushless DC motor.…”

Section: (A) Series Elastic Actuation (Sea)mentioning

confidence: 99%

Advances in Propulsive Bionic Feet and Their Actuation Principles

Cherelle

Mathijssen

Wang

et al. 2014

Advances in Mechanical Engineering

View full text Add to dashboard Cite

In the past decades, researchers have deeply studied pathological and nonpathological gait to understand the human ankle function during walking. These efforts resulted in the development of new lower limb prosthetic devices aiming at raising the 3C-level (control, comfort, and cosmetics) of amputees. Thanks to the technological advances in engineering and mechatronics, challenges in the field of prosthetics have become an important source of interest for roboticists. Currently, most of the bionic feet are still on a research level but show promising results and a preview of tomorrow's commercial prosthetic devices. In this paper, the authors present the current state-of-the-art and the latest advances in propulsive bionic feet with its actuation principles. The context of this review study is outlined followed by a brief description of the basics in human biomechanics and criteria for new prosthetic designs. A new categorization based on the actuation principle of propulsive ankle-foot prostheses is proposed. Based on simulations, the general principles and benefits of each actuation method are explained. The corresponding latest advances in propulsive bionic feet are presented together with their main characteristics and scientific outcomes. The authors also propose to the reader a comparison analysis of the presented devices with a discussion of the general tendencies in new prosthetic feet.

show abstract

“…The possibilities of this approach have been shown by several authors already, including (Au & Herr, 2008), (Holgate et al, 2008), (Brown & Ulsoy, 2011), (Plooij & Wisse, 2012) and (Rouse et al, 2013). The use of series and parallel springs in actuation brings along several additional design constraints and is not the focus of this chapter.…”

Section: Introductionmentioning

confidence: 99%

“…There are other approaches that can provide (partial) solutions to help operate electric motors in their more energy efficient range of operation. For specific applications, springs can be added in series or paralel to the drive to reduce the load on the actuator (see for example (Holgate et al, 2008), (Folkertsma et al, 2012), (Brown & Ulsoy, 2011), (Rouse et al, 2013) and (Au & Herr, 2008)). By including a variable stiffness actuator or module, the compliance can be continuously adjusted to best fit the needs of the application (see, for example: (Groothuis et al, 2012), (Fumagalli et al, 2012), (Jafari et al, 2010(Jafari et al, , 2011 and (Kim & Song, 2010)).…”

Section: Implications For the Research Fieldmentioning

confidence: 99%

Controlled passive actuation : concepts for energy efficient actuation using mechanical storage elements and continuously variable transmissions

Dresscher¹

View full text Add to dashboard Cite

SummaryEnergy autonomous robots need to take care of their own energy supply. In the absence of a charging station, the robot will have to replenish its energy in other ways. Alternative energy sources available to a robot in an outdoor environment may include unrefined biomass, sun and wind. As these energy sources are limited, energy efficiency of mobile robots is of key importance.With this research, we want to make a step toward energy autonomous legged robots. For this, we have two key objectives: increase insight in the mechanisms of energy loss and contribute toward the improvement of energy efficiency.In the first part of this thesis, the energy losses in legged robots are discussed. The active supporting of the system mass and the additional movement of the legs contribute to the high energy consumption in legged vehicles. However, how significant the contributions of the various causes of energy loss are, is not well understood. We investigate the mechanisms of energy loss in electric actuators to understand their contribution to energy (in)efficiency. As a part of this effort, a method to select a motor-gearbox combination for energy efficiency is presented and evaluated to show the possible impact. We conclude that for most robotic applications, electric actuators are the dominant cause of energy losses. Selecting a motor-gearbox combination for energy efficiency can provide a significant improvement in the efficiency. However, the energy losses in the motor-gearbox combination remain significant.As an alternative to using only electric actuators for actuation, an actuation principle that incorporates a mechanical storage element and a Continuously Variable Transmission (CVT) in the drive-train is discussed. This actuation principle is named Controlled Passive Actuation (CPA). The envisioned benefits are twofold: first, separation of the energy supply function and the servoing function enables using the electric actuator in its most efficient range of operation; and, second, by incorporating the capability to recycle energy within the mechanical domain, the energy loss in the electric actuator can be avoided.An important component in this actuation principle is the CVT and in the ii second part of this thesis, two CVT's that were designed for application in Controlled Passive Actuation are discussed. The first design in a lever with a pivot that moves along the lever. It is shown that the design is conceptually suitable for application in Controlled Passive Actuation and that the mechanical design needs improvement. The second design is based on two spheres of which the relative orientation can be changed to adapt the transmission ratio. This concept is named Dual-Hemi CVT. A prototype was built and experimental results show that it is suitable for application in CPA.In the third part of this thesis, two versions of CPA are discussed. In the first version of CPA, a flywheel is used as mechanical storage element. By changing the rate of the transmission ratio of the Continuously Variable Transmission,...

show abstract

The SPARKy (Spring Ankle with Regenerative kinetics) project: Choosing a DC motor based actuation method

Cited by 43 publications

References 16 publications

Modeling and design of geared DC motors for energy efficiency: Comparison between theory and experiments

Modeling and design of geared DC motors for energy efficiency: Comparison between theory and experiments

Advances in Propulsive Bionic Feet and Their Actuation Principles

Controlled passive actuation : concepts for energy efficient actuation using mechanical storage elements and continuously variable transmissions

Contact Info

Product

Resources

About