Optimal velocity profile generation for given acceleration limits: theoretical analysis

2005 ◽  
Author(s):  
E. Velenis ◽  
P. Tsiotras
Keyword(s):  
Theoretical Analysis ◽  
Velocity Profile ◽  
Optimal Velocity

scholarly journals Optimal velocity profile for a cable car passing over a support

2019 ◽  
Vol 73 ◽  
pp. 366-372 ◽  
Author(s):  
M. Wenin ◽  
A. Windisch ◽  
S. Ladurner ◽  
M.L. Bertotti ◽  
G. Modanese
Keyword(s):  
Velocity Profile ◽  
Optimal Velocity

Lower Limb Force, Velocity, Power Capabilities during Leg Press and Squat Movements

2017 ◽  
Vol 38 (14) ◽  
pp. 1083-1089 ◽  
Author(s):  
Johnny Padulo ◽  
Gian Migliaccio ◽  
Luca Ardigò ◽  
Bruno Leban ◽  
Marco Cosso ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Effect Size ◽  
Power Output ◽  
Lower Limb ◽  
Maximal Power ◽  
Maximal Power Output ◽  
Optimal Velocity ◽  
Leg Press ◽  
Maximal Force ◽  
Force Velocity

AbstractThe aim was to compare lower-limb power, force, and velocity capabilities between squat and leg press movements. Ten healthy sportsmen performed ballistic lower-limb push-offs against 5-to-12 different loads during both the squat and leg press. Individual linear force-velocity and polynomial power-velocity relationships were determined for both movements from push-off mean force and velocity measured continuously with a pressure sensor and linear encoder. Maximal power output, theoretical maximal force and velocity, force-velocity profile and optimal velocity were computed. During the squat, maximal power output (17.7±3.59 vs. 10.9±1.39 W·kg−1), theoretical maximal velocity (1.66±0.29 vs. 0.88±0.18 m·s−1), optimal velocity (0.839±0.144 vs. 0.465±0.107 m·s−1), and force-velocity profile (−27.2±8.5 vs. −64.3±29.5 N·s·m−1·kg−1) values were significantly higher than during the leg press (p=0.000, effect size=1.72–3.23), whereas theoretical maximal force values (43.1±8.6 vs. 51.9±14.0 N·kg−1, p=0.034, effect size=0.75) were significantly lower. The mechanical capabilities of the lower-limb extensors were different in the squat compared with the leg press with higher maximal power due to much higher velocity capabilities (e.g. ability to produce force at high velocities) even if moderately lower maximal force qualities.

A theoretical analysis of the calendering of Ellis fluid

2016 ◽  
Vol 33 (2) ◽  
pp. 207-226 ◽  
Author(s):  
Muhammad Asif Javed ◽  
Nasir Ali ◽  
Muhammad Sajid
Keyword(s):  
Theoretical Analysis ◽  
Velocity Profile ◽  
Pressure Gradient ◽  
Pressure Distribution ◽  
Sheet Thickness ◽  
Power Input ◽  
Lubrication Approximation ◽  
Material Parameters ◽  
Operating Variables ◽  
Roll Separating Force

We present a theoretical analysis of calendering of Ellis fluid based on lubrication approximation. The equations governing the flow are nondimensionalized and solved to get closed form expressions of velocity and pressure gradient. Runge–Kutta algorithm is employed to compute the pressure distribution. The operating variables which are used in the calendering process, i.e. roll-separating force, power input to the rolls and exiting sheet thickness are calculated. The influence of the material parameters on the velocity profile, pressure gradient, pressure distribution and operating variables is shown graphically and discussed in detail.

scholarly journals How muscles deal with real-world loads: the influence of length trajectory on muscle performance

1999 ◽  
Vol 202 (23) ◽  
pp. 3377-3385 ◽  
Author(s):  
R.L. Marsh
Keyword(s):  
Velocity Profile ◽  
Real World ◽  
Skeletal Muscles ◽  
External Environment ◽  
The Body ◽  
Muscle Performance ◽  
Force Output ◽  
Optimal Velocity ◽  
Level Running

The performance of skeletal muscles in vivo is determined by the feedback received when the muscle interacts with the external environment via various morphological structures. This interaction between the muscle and the ‘real-world load’ forces us to reconsider how muscles are adapted to suit their in vivo function. We must consider the co-evolution of the muscles and the morphological structures that ‘create’ the load in concert with the properties of the external environment. This complex set of interactions may limit muscle performance acutely and may also constrain the evolution of morphology and physiology. The performance of skeletal muscle is determined by the length trajectory during movement and the pattern of stimulation. Important features of the length trajectory include its amplitude, frequency, starting length and shape (velocity profile). Many of these parameters interact. For example, changing the velocity profile during shortening may change the optimum values of the other parameters. The length trajectory that maximizes performance depends on the task to be performed. During cyclical work, muscles benefit from using asymmetric cycles with longer shortening than lengthening phases. Modifying this ‘sawtooth’ cycle by increasing the velocity during shortening may further increase power by augmenting force output and speeding deactivation. In contrast, when accelerating an inertial load, as in jumping, the predicted ‘optimal’ velocity profile has two peak values, one early and one late in shortening. During level running at constant speed, muscles perform tasks other than producing work and power. Producing force to support the body weight is performed with nearly isometric contractions in some of the limb muscles of vertebrates. Muscles also play a key role in producing stability during running, and the intrinsic properties of the musculoskeletal system may be particularly important in stabilizing rapid running. Recently, muscles in running invertebrates and vertebrates have been described that routinely absorb large amounts of work during running. These muscles are hypothesized to play a key role in stability.

Combined time/location optimization of robotic motions with specified paths and velocity profiles

Robotica ◽  
1989 ◽  
Vol 7 (4) ◽  
pp. 309-314
Author(s):  
L. Beiner
Keyword(s):  
Velocity Profile ◽  
Numerical Integration ◽  
Parameter Optimization ◽  
Optimization Approach ◽  
Constant Acceleration ◽  
Optimal Velocity ◽  
Location Optimization ◽  
Switching Curve ◽  
Time Minimization ◽  
Robot Path

SUMMARYA parameter optimization approach to the time-minimization of robotic motions along specified paths is presented for the case when: (i) the velocity profile is a prescribed sequence of constant acceleration/deceleration segments with unspecified, but bounded vertex velocities at given path stations; (ii) the relative robot/path location can be varied. Such optimizations occur when technological requirements impose a certain velocity profile along the path due to velocity and acceleration constraints. Full nonlinear manipulator dynamics and path parameterization are used to determine the optimal velocity profile and robot location consistent with the actuator/configuration limitations. No numerical integration or search for switching curve are involved in the solution. Examples of time-and-location optimized robotic motions with specified velocity profile are presented.

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