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This study aims to develop a program-loading spectrum for the accelerated durability test of automotive components, with the lower control arm of a suspension as an example. Spectrum development is divided into three parts, namely, load spectrum acquisition, spectrum preprocessing, and program-loading spectrum development. Based on the strengthening property of structural low-amplitude loads under constant and random loadings, a program-loading spectrum-development method considering the strengthening effect of low-amplitude loads (SLAL) below the fatigue limit is proposed. Meanwhile, an equivalent strengthening methodology is considered during spectrum development. The number of loading cycles is decreased, and the bench test time is notably reduced by adjusting strengthening loads to the most effective level. The bench test proved that the influence of SLAL during spectrum development can simulate actual load conditions more effectively and precisely. Thus, this method can accurately predict fatigue failure from the durability test and can efficiently reduce durability test time.

Formula SAE is a Student project that involves a complete design and fabrication of an open wheel formula-style racecar. This paper will cover the suspension geometry and its components, which include the control arm, uprights, spindles, hubs, and pullrods. The 2002 Lawrence Technological Universities Formula SAE car will be used as an example throughout this paper.

International audience; The present study tested whether vestibular input can be processed on-line to control goal-directed arm movements towards memorized visual targets when the whole body is passively rotated during movement execution. Subjects succeeded in compensating for current body rotation by regulating ongoing arm movements. This performance was compared to the accuracy with which subjects reached for the target when the rotation occurred before the movement. Subjects were less accurate in updating the internal representation of visual space through vestibular signals than in monitoring on-line body orientation to control arm movement. These results demonstrate that vestibular signals contribute to motor control of voluntary arm movements and suggest that the processes underlying on-line regulation of goal-directed movements are different from those underlying navigation-like behaviors.

Fatigue was induced in the triceps brachii of the experimental arm by a regimen of either eccentric or concentric muscle actions. Estimates of force were assessed using a contralateral limb-matching procedure, in which target force levels (25 %, 50 % or 75 % of maximum) were defined by the unfatigued control arm. Maximum isometric force-generating capacity was reduced by 31 % immediately following eccentric contractions, and remained depressed at 24 (25 %) and 48 h (13 %) post-exercise. A less marked reduction (8.3 %) was observed immediately following concentric contractions. Those participants who performed prior eccentric contractions, consistently (at all force levels), and persistently (throughout the recovery period), overestimated the level of force applied by the experimental arm. In other words, they believed that they were generating more force than they actually achieved. When the forces applied by the experimental and the control arm, were each expressed as a proportion of the maximum force that could be attained at that time, the estimates matched extremely closely. This outcome is that which would be expected if the estimates of force were based on a sense of effort. Following eccentric exercise, the amplitude of the EMG activity recorded from the experimental arm was substantially greater than that recorded from the control arm. Cortically evoked potentials recorded from the triceps brachii (and extensor carpi radialis) of the experimental arm were also substantially larger than those elicited prior to exercise. The sense of effort was evidently not based upon a corollary of the central motor command. Rather, the relationship between the sense of effort and the motor command appears to have been altered as a result of the fatiguing eccentric contractions. It is proposed that the sense of effort is associated with activity in neural centres upstream of the motor cortex.

Control Arm (CA) of a suspension plays an important role in the automotive ride comfort and handling stability. In this paper, the topology optimization model including ball joints and bushing for topology optimization of an aluminium CA is established, where a ball joint is simplified as rigid elements and the elastic properties of a rubber bushing are estimated using Mooney-Rivlin constitutive law. A method for treating with multiple loads in topology optimization of CA is presented. Inertia relief theory is employed in the FEA model of the CA in order to simulate the large displacement motion characteristics of the CA. A CA is designed based on the topology optimization results, and the strength, natural frequency, and rigidity of the optimized CA are calculated. The calculated results show that the performances of the optimized CA with the proposed model meet the predetermined requirements.

This paper aims to identify the steering drift of a small passenger vehicle under severe straight braking. Steering drift is analysed by gyro and wheel tracker measurements of dynamic wheel alignments, and when compliance is done by Kinematic and Compliance (KC subsequently, the toe angle becomes toe-out owing to the wheel bump stroke. To investigate the contribution of suspension parameters that may be difficult to control in field tests, bushing stiffness of the lower control arm, kingpin offset at the ground, caster angle, bump toe angle and wheel weight are simulated in a multi-body software environment. The results show that the dominant factors are the bump toe, caster and the wheel weight difference between the left and right wheels. This approach is useful in setting proper suspension geometry at the stage of conceptual chassis design.

6512 Background: The use of randomized phase II designs with an experimental arm and a standard-treatment control arm (R2PII) instead of a conventional single-arm design is clearly increasing in oncology. In practice, sample size, related cost issues, the belief that historical controls are adequate, and the use of a standard-treatment control arm in a phase II setting are frequently raised objections to R2PII trials. As the expense and complexity of definitive phase III trials increase, the ability of phase II trials to provide reliable and accurate results is critical. Methods: We investigated the ability of single arm vs R2PII trials to provide accurate conclusions by modeling variability in historical controls, patient outcome drifts independent of the tested therapy, and patient selection effects. Simulations compared R2PII and single-arm designs with binary endpoints under realistic parameters (e.g. alpha = beta = 0.10, historical control success rate = 20%, target success rate = 40%). Results: In the absence of variability in historical controls, estimated false positive and negative rates in both designs mirror the designated specifications. However, even in the presence of a modest drift effect in the population (mean 5% absolute shift in true control success rate), the false positive rate in single-arm designs is inflated two to three fold (to 20%-30%), while the R2PII retains the desired error rates. Greater confidence in historical controls in the single-arm design corrects only a small portion of the deviations. Increasing the sample size in each trial inflates the false positive error rate further to as much as 50%. Varying several sets of parameters gave similar results. Conclusions: In the presence of variability in historical controls, patient drift and/or selection effects, the false positive error rate of a single arm design is unacceptably high. In contrast, the R2PII design is reliable and robust despite the complexities in patient outcome drift and selection effects, and variability in historical control success rates. Given the rapid improvements in outcomes of many tumor types, the R2PII design should be the preferred method to evaluate novel agents in oncology in spite of the associated costs and the use of a reference control arm. No significant financial relationships to disclose.

We report noise and detection limitations in cantilever-based immunomagnetic biosensors. A differential cantilever system with sensing and control arms was used whereby the control arm was passivated with bovine serum albumin BSA and the sensing arm was functionalized with biotin-BSA. Streptavidin-coated magnetic beads were exposed to cantilever arms. An oscillatory magnetic field induced a magnetic force on the beads which caused a relative deflection of the sensing arm. Increasing the excitation frequency suppressed the 1/ f noise by 100-fold, resulting in a deflection resolution of 0.065 Å in air.

Therapeutic endoscopy in the new millennium will undoubtedly be more complex and challenging. New techniques may require simultaneous use of multiple endoscopic accessories. This would necessitate a device capable of stabilizing a flexible endoscope and freeing up the endoscopists' hands. Aim: To design a flexible endoscope stand that would secure an endoscope in any given position. Method: A rigid post and clamp device was fashioned and fitted onto a stabilizing Plexiglas plate which is placed under the patient. A screw-type clamp contains the endoscope control arm. Position of the endoscope control arm can be adjusted by raising and lowering the clamping mechanism. The clamping mechanism provides 360° rotation with the ability to fix the endoscope control arm (handle) in any desired position. The device was then assessed during complex therapeutic procedures using dual channel endoscopies with simultaneous use of two accessories. Results: The stand successfully freed up the endoscopists' hands for accessory manipulation and other activities requiring interruption of the endoscopic procedure. It provided this function while at the same time maintaining the position of the endoscope accurately and safely within the patient. The stand proved to be portable, durable, easy to disinfect and required only the weight of the patient for stability. Device function was limited when excess rotational torque of the endoscope insertion tube was needed. The cost of the stand materials was $270. Conclusion: 1) The flexible endoscope stand meets an evolving need to facilitate complex endoscopic procedures that require the simultaneous use of both hands of the endoscopist in order to control two accessories or the secondary use of a mini-scope. 2) The stand can also be employed during an interruption of a procedure to attend to patient needs. 3) Furthermore, the use of such a device may also have the added benefit of reducing the growing risk of repetitive use syndrome during lengthy procedures. (The Apollo Group: Sydney Chung, Peter Cotton, Christopher Gostout, Robert Hawes, Anthony Kalloo, Pankaj Pasricha, Thadeus Trus)

Publisher Summary This chapter discusses freeing the machine shop worker from repetitious, hard, manual operations in favor of using his capability to perform monitoring and controlling functions. In the assembly, plants automation progressed at a much slower rate. The sequence of motions executed by a worker in the assembly process is much more difficult and expensive reproduce by machine. In assembly of semitrailing control arm for rear axle, the semitrailing control arm, rear axle shaft flange, tapered roller bearing, rubber bearings, brake carrier, and various small parts are assembled and the play of the wheel bearing is adjusted and checked. The assembly of the front stub axle includes attaching the front wheel hub to the brake disc and assembling these with the steering knuckle, brake cover plate, and dust cap. The differential gear assembly section put was into operation at the beginning of 1977. This assembly facility replaced the previous conveyer line assembly for our high-volume production line.

Publisher Summary This chapter discusses freeing the machine shop worker from repetitious, hard, manual operations in favor of using his capability to perform monitoring and controlling functions. In the assembly, plants automation progressed at a much slower rate. The sequence of motions executed by a worker in the assembly process is much more difficult and expensive reproduce by machine. In assembly of semitrailing control arm for rear axle, the semitrailing control arm, rear axle shaft flange, tapered roller bearing, rubber bearings, brake carrier, and various small parts are assembled and the play of the wheel bearing is adjusted and checked. The assembly of the front stub axle includes attaching the front wheel hub to the brake disc and assembling these with the steering knuckle, brake cover plate, and dust cap. The differential gear assembly section put was into operation at the beginning of 1977. This assembly facility replaced the previous conveyer line assembly for our high-volume production line.

To satisfy the objectives of Chrysler's new generation of compact vehicles, a unique front suspension system was created. This system has achieved an outstanding level of ride comfort while providing significant advantages in the basic vehicle packaging. The key to the system is the transverse torsion bar and bushings which serve the dual function of suspension spring and fore and aft restraint for the lower control arm. Producing this torsion bar in mass production required advances in both engineering and manufacturing technology. /GMRL/

Simulations are performed for the squeeze casting of AM60 and AZ91 automotive control arms. Advanced feeding flow and stress models are used within commercial casting simulation software to predict shrinkage porosity and hot tears. The simulations are validated through comparisons with observations made on experimental castings. Generally good agreement is obtained between the measured and predicted defect locations and extents. Design and process changes are introduced to mitigate the shrinkage and hot tear problems in these castings. The comparisons in the present study establish considerable confidence in the ability of casting simulation to predict shrinkage and hot tears in squeeze casting of magnesium alloys.

In this article, two new compliant control architectures are introduced that utilize null space solutions to decouple force and position control. They are capable to interact with uncertain surfaces and environments with varying materials and require fewer parameters to be tuned than the common architectures – hybrid or impedance control. The general concept behind these approaches allows to consider manipulators with six degrees of freedom as redundant by creating a virtual redundancy with a reduced work space. It will be demonstrated that the introduced approaches are superior regarding orthogonal separation of the Cartesian degrees of freedom and avoid inner singularities. To demonstrate their performance, the controllers are tested on a standard industrial robot (Stäubli, RX90B, six degrees of freedom) that actuates two different biomechanically inspired models of the human knee joint.