Negative Input Shaped Commands for Unequal Acceleration and Braking Delays of Actuators

Sung, Yoon-Gyung; Jang, Wan-Shik; Kim, Jae-Yeol

doi:10.1115/1.4039367

Cited by 3 publications

(5 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To develop an input shaper for such a nonlinear input command profile, the input command is transformed and simplified into a ramp shape, as depicted in Figure 3. This approach, with an equivalent constraint, provides a solution process that can be reformulated to develop an input shaper for the distorted command [11]. In Figure 2, V d represents the desired velocity of the actuator and v s represents the velocity shaped by the input shaper.…”

Section: Robust Input Shapers For Acceleration-limit Actuatorsmentioning

confidence: 99%

“…Even if the EI and ZVD shapers produce longer insensitivity than the ZV shaper at 𝑉 = 5%, these input shapers are developed under the assumption of linear system theory which means that their robustness performance is questionable for nonlinear dynamics. Considering the nonlinear dynamics of actuators, several input shapers have been proposed for ramp [10,11], first-order [12,13], and asymmetric 2nd-order [14] actuators. However, nonlinear dynamics can be attributed to discontinuous nonlinearities within a system, such as backlash, saturation, rate-limiting, and dead-zone.…”

Section: Introductionmentioning

confidence: 99%

“…A ramp-step function is employed to approximate the response of the acceleration-limit actuator. Second, two types of robust input shapers are strategically developed with the utilization of the analytical Considering the nonlinear dynamics of actuators, several input shapers have been proposed for ramp [10,11], first-order [12,13], and asymmetric 2nd-order [14] actuators. However, nonlinear dynamics can be attributed to discontinuous nonlinearities within a system, such as backlash, saturation, rate-limiting, and dead-zone.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Robust Input Shapers for Acceleration-Limit Actuators

Kim,

Sung

2023

Applied Sciences

Self Cite

View full text Add to dashboard Cite

In this study, robust input shapers consisting of only three impulses are proposed for reducing the residual deflection of flexible systems with acceleration-limit actuators, while maintaining the robust control performance associated with system parameter uncertainties. The unequal acceleration and braking delays of such actuators can produce large residual oscillations owing to the distortion of shaped commands in undamped flexible systems during rest-to-rest operations. Thus, two types of robust input shapers are analytically developed using a phase vector approach with the adoption of the ramp-step function to approximate the dynamics of acceleration-limit actuators and with the utilization of conventional robust shapers. The proposed robust input shapers are numerically evaluated with respect to the command completeness effect, and the residual deflection and parameter uncertainties are experimentally validated using a mini bridge crane. The proposed robust shapers exhibit a higher robustness performance than classical robust input shapers.

show abstract

Section: Robust Input Shapers For Acceleration-limit Actuatorsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Robust Input Shapers for Acceleration-Limit Actuators

Kim,

Sung

2023

Applied Sciences

Self Cite

View full text Add to dashboard Cite

show abstract

“…Advances in robustness dealing with actual trapezoidal profiles instead of theoretical pulses corresponding to Bang-Bang optimal time negative input shaping are remarkable as in the work of [ 26 ], however the control fall on proprietary closed hardware.…”

Section: Conceptualization: Robust Input Shapingmentioning

confidence: 99%

Dynamics and Embedded Internet of Things Input Shaping Control for Overhead Cranes Transporting Multibody Payloads

Peláez

Vaugan

Izquierdo

et al. 2018

Sensors

View full text Add to dashboard Cite

Input shaping is an Optimal Control feedforward strategy whose ability to define how and when a flexible dynamical system defined by Ordinary Differential Equations (ODEs) and computer controlled would move into its operative space, without command induced unwanted dynamics, has been exhaustively demonstrated. This work examines the issue of Embedded Internet of Things (IoT) Input Shaping with regard to real time control of multibody oscillatory systems whose dynamics are better described by differential algebraic equations (DAEs). An overhead crane hanging a double link multibody payload has been appointed as a benchmark case; it is a multibody, multimode system. This might be worst scenario to implement Input Shaping. The reasons can be found in the wide array of constraints that arise. Firstly, the reliability of the multibody model was tested on a Functional Mock-Up Interface (FMI) with the two link payload suspended from the trolley by comparing the experimental video tapping signals in time domain faced with the signals extracted from the multibody model. The FFTs of the simulated and the experimental signal contain the same frequency harmonics only with somewhat different power due to the real world light damping in the joints. The application of this approach may be extended to other cases i.e., the usefulness of mobile hydraulic cranes is limited because the payload is supported by an overhead cable under tension that allows oscillation to occur during crane motion. If the payload size is not negligible small when compared with the cable length may introduce an additional oscillatory mode that creates a multibody double pendulum. To give the insight into the double pendulum dynamics by Lagrangian methods two slender rods as payloads are analyzed dealing with the overhead crane and a composite revolute-revolute joint is proposed to model the cable of the hydraulic crane, both assumptions facilitates an affordable analysis. This allows developing a general study of this type of multibody payloads dynamics including its normal modes, modes ratios plus ranges of frequencies expected. Input Shapers were calculated for those multimodes of vibration by convolving Specified Insensitivity (SI) shapers for each mode plus a novel Direct SI-SI shaper well suited to reduce the computational requirements, i.e., the number of the shaper taps, to carry out the convolution sum in real time by the IoT device based on a single microcontroller working as the command generator. Several comparisons are presented for the shaped and unshaped responses using both the multibody model, the experimental FMI set-up and finally a real world hydraulic crane under slewing motion commanded by an analog Joystick connected by two RF modules 802.15.4 to the IoT device that carry out the convolution sum in real time. Input Shaping improves the performances for all the cases.

show abstract

“…When an actuator nonlinearity deviates an input-shaped command, the oscillation-reducing performance of the shaped command can be significantly degraded. To reduce the detrimental effects of actuator nonlinearities, input shaper redesign techniques have been established from the perspective of rate limits [22,23], backlash [24], and Coulomb friction [25,26]. In addition, on-off shaping techniques were developed for non-ideal input commands distorted by asymmetrical delayed first-order actuators [27] and second-order actuators [28].…”

Section: Introductionmentioning

confidence: 99%

Deflection Reduction Shaping Commands with Asymmetric First-Order Actuators

Sung

Kim

2019

Applied Sciences

Self Cite

View full text Add to dashboard Cite

In this paper, two approaches for generating deflection reduction shaping commands are proposed to reduce the transient and residual deflections of flexible systems subject to asymmetric first-order actuators. The commands are limited-state in that they consist of two positive actuations of different magnitudes and one negative actuation, similar to on-off-on commands. Standard on–off commands that are commonly used in robots, cranes, and spacecrafts can degrade the control performance of conventional input-shaped commands and cause detrimental damage resulting from large transient deflections of flexible structures due to asymmetric first-order actuators. Therefore, to cope with the performance degradation resulting from the effects of first-order actuators, an approximated closed-form solution and a numerically optimized approach for deflection reduction shaping commands are presented with an exponential function, final impulse magnitude modification of an input shaper is determined by a transient deflection constraint and a phasor vector approach. The performance assessment showed that the approximated analytical approach has an advantage in real-time control applications. The characteristics of the proposed deflection reduction shaping commands are analyzed with respect to system parameters, deflection reduction ratios, and actuator time constants. The proposed command shaping techniques are numerically evaluated using a pendulum system and are experimentally validated on a mini-bridge crane.

show abstract

Negative Input Shaped Commands for Unequal Acceleration and Braking Delays of Actuators

Cited by 3 publications

References 12 publications

Robust Input Shapers for Acceleration-Limit Actuators

Robust Input Shapers for Acceleration-Limit Actuators

Dynamics and Embedded Internet of Things Input Shaping Control for Overhead Cranes Transporting Multibody Payloads

Deflection Reduction Shaping Commands with Asymmetric First-Order Actuators

Contact Info

Product

Resources

About