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An experimental computer programmed system has been developed to aid in the analysis of planar and spatial linkage mechanisms. Linkages are described to the system in a simple FORTRAN-like language. The system compiles and solves the equations, which define position, motion, and force for the linkage. The design of the system is based on concepts developed for computer aids to engineering in other fields and on recent developments of analytic methods for mechanical design. Basic requirements of any design analysis system were identified during the programming of the system.

This is the sixth paper in a series of six papers describing the KAM (Kinematic Analysis Method) system being developed by the IBM Automotive and Machine Design Project. The system will be used in the analysis of most industrial linkages for which an explicit position solution exists. This paper describes the application of vector algebra to a linkage mechanism that is more complex than those classes acceptable to the KAM system. The intent here is to outline the methods developed, and their advantages, for such an application of vector algebra.

This paper discusses the use of vector algebra to obtain the motion of elements of linkages falling within the scope of the KAM system. Both the mathematical and the programming techniques used to obtain the velocities and accelerations are discussed in detail. The procedure used results in a set of linear equations and thus provides an exact solution.

The program for force and torque analysis of planar and spatial linkages is part of the KAM (Kinematic Analysis Method) system. A general set of force and moment equilibrium equations has been developed. The program generates the parameters for the equations from a computer stored description (the plex) of a linkage and then solves the equations for all static forces and torques.

This is the third paper in a series of six papers describing the KAM (Kinematic Analysis Method) system, which is a computer oriented generalized approach to solving linkage mechanisims consisting of single or multiple series loops of one or more degrees of freedom. The generalized position solution section of KAM is described herein along with its scope and limitations

This paper presents the system concepts of the Kinematic Analysis Method (KAM). The KAM system enables the design engineer to automate the analysis of a wide variety of mechanical linkages. This is the second in a series of papers from the IBM Automotive and Machine Design Group, which originated the KAM system.

The kinematic model of the double roller tripod joint is established in order to analyze its kinematic characteristics and provide theoretical basis for its application and improvement. By means of spatial coordinate transformation, the translational and rotational motion equations of the rollers relative to the tracks and trunnions, the motion equation of the center of the tripod and the equations of the input/output angular displacement error and bending angle are derived. The motion simulation of the double roller tripod universal joint was carried out in ADAMS so as to verify the established kinematic model. The results show that the rollers of the double roller tripod joint only have periodic translational motions relative to the tracks while the rollers have both periodic translational and rotational motions relative to the trunnions. The tripod’s center does the circular motion on the tripod plane with the angular velocity 3 times of the input angular velocity.

The Chain-Wave Transmission (CWT) is a new type of harmonic drives, which was created at the Armenian Agricultural Academy. In the paper is considered the motion of elements and are constructed motion trajectories of the chain's rollers center at various values of the waves number and multiplicity factor of the CWT. There are received also expressions for determination of displacements, speeds and accelerations of the chain's rollers center depending on rotation angle of the waves generator, is given their analysis and on their basis are specified the basic parameters of the CWT.

This paper investigates the chordal action and transmission errors of a simple silent chain system. The chordal action analysis is based on the tooth contact analysis of the chain with the driving sprocket. Chordal action of different contact patterns is compared. The result indicates that chordal action of the case in which at most two link pates are in contact is significantly reduced. The transmission error analysis is based the tooth contact analysis of the chain with both the driving and driven sprockets. The result shows how the angular motion of the driven sprocket deviates while the driving sprocket rotates at a constant speed.

Variable valve Actuation (VVA) systems are being increasingly used in IC engine. Recently novel valve actuation mechanism like continuous variable valve lift (CVVL) is being explored to regulate engine output without conventional throttle valve and this reduces the pumping losses especially at part load in SI engines. In this paper numerical model for the kinematic analysis of a CVVL mechanism is presented using MATLAB. It consists of eccentric shaft fitted with a series of intermediate rocker arm, which in turn control the degree of valve lift. The main characteristic of this mechanism is that it uses a general curve contact between the elements, which is determined using theory of envelope curve. The mechanism’s system of equations solving principle is based on the Newton-Raphson numerical method.

Given the quantity and severity of head injuries to pedestrians in vehicle-to-pedestrian collisions, human pedestrian finite element models and pedestrian dummies must possess a biofidelic head/neck response to accurately reproduce head-strike kinematics and kinetics. Full-scale pedestrian impact experiments were performed on post-mortem human surrogates (PMHS) using a mid-sized sport utility vehicle and a small sedan. Kinematics of the head and torso were obtained with a six-degree-of-freedom (6DOF) cube, which contained three orthogonally mounted linear accelerometers and three angular rate sensors. The goal of the current study was to present a methodology for analyzing the data obtained from the sensors on each cube, and to use the kinematics data to calculate spatial trajectories, as well as linear velocities and angular accelerations of the head and T1 vertebra.

Steering of non-driven axles of semi-trailer results in improvement of maneuverability during negotiating sharp turn and reduces tyre drag and wear by relieving locked-in forces in comparison to non-steered axles. Among few, command steering mechanism is reported to be most efficient method of steering of articulated vehicles. In this type, the axles of semi-trailer are steered in relation with the articulation of tractor. The articulation angle of tractor is sensed by an actuation mechanism integrated on trailer at fifth wheel location and transferred hydraulically to the steering linkages. Mathematical equations have been developed based on Ackerman's Principle to estimate theoretical steering angle when Tractor-Trailer negotiate any turn. Steering linkage geometry has been conceptualised, kinematically modelled and analysed by using ADAMS. Equations developed for theoretical steering angles are incorporated in ADAMS as run time functions.

Over the years, commercial vehicles, especially tractor-semitrailer combinations have become larger and longer. With the increasing demand for their accessibility in remote locations, these vehicles face the problem of off-tracking, which is the ensuing difference in path radii between the front and rear axles of a vehicle as it maneuvers a turn. Apart from steering the rear axle of the semitrailer, one of the feasible ways of mitigating off-tracking is to shift the fifth wheel coupling rearwards. However, this is limited by the distribution of the semitrailer’s load between the two axles of the tractor; any rearward shift of the fifth wheel coupling results in the reduction of the total static load on the tractor’s front axle and hence available traction. This may in turn lead to directional instability of the vehicle. In the present work, a new model of the fifth wheel coupling is proposed which the authors call Split fifth wheel coupling (SFWC).

Tripode Joints are said to be Constant Velocity Joints, but in actual employment, they have some velocity fluctuation. Analysis was made of the effects of the twist of the intersecting planes, 120° dividing errors and deviation of the pitch radius on the velocity fluctuation and the joint design. Instead of the conventional tripode joints with half side variable pitch radius (HVPR) profile, the tripode joints with both side variable pitch radius (BVPR) profile have been proposed, which remarkably reduce velocity fluctuation and provide more design freedom.

Gantry robots are mainly employed for applications requiring large workspace, with limited higher manipulability in one direction than the others. The Gantries offer very good mechanical stiffness and constant positioning accuracy, but low dexterity. Common gantries are CNC machines with three translational joints XYZ (3DOF) and usually with an attached wrist (+3DOF). The translational joints are used to move the tool in any position in the 3D workspace. The wrist is used to orient the tool by rotation about X, Y and Z axis. This standard kinematic structure (3T3R) produces a rectangular workspace. In this paper a full kinematic model for a 6DOF general CNC (gantry) machine is presented, along with the Jacobian matrix and singularity analysis. Using Denavit-Hartenberg convention, firstly, the general kinematic structure is presented, in order to assign frames at each link. The forward kinematic problem is solved using Maple 17 software.

The next generation of pressure suits must enable large-scale planetary Extra-Vehicular Activities (EVA). Astronauts exploring the moon and Mars will be required to walk many kilometers, carry large loads, perform intricate experiments, and extract geological samples. Advanced pressure suit architectures must be developed to allow astronauts to perform these and other tasks simply and effectively. The research developed here demonstrates integration of robotics technology into pressure suit design. The concept of a robotically augmented pressure suit for planetary exploration has been developed through the use of analytical and experimental investigations. Two unique torso configurations are examined, including a Soft/Hard Upper Torso with individually adjustable bearings, as well as advances in Morphing Upper Torso research, in which an all-soft torso is analyzed as a system of interconnected parallel manipulators.

The design of control arms of vehicle's front independent suspension is a complicated and constrained optimization problem with multi-objective functions and multi-variables. By use of linear transformation theory, a general calculating method and the relevant computer programme for kinematics within the range of displacement of all kinds of independent and dependent suspensions are worked out first, which can also be used to calculate the values of objective functions in the process of optimization. Based on the analysis of orthogonal experimental designs (factorial experiments), a sort of three steps design optimization of control arms of wishbone type front independent suspension and the relevant computer programme are then presented, which can also be used for the design of other types of independent suspensions.

Tires have been taking an important role in vehicle safety in the last years. A lot of efforts have been taken in the way that we can understand, predict and follow its behavior, in the way that this could be useful for vehicle safety increasing. In this direction, several models describe the tire interaction with ground, considering the steering angle, pressure, temperature, friction coefficient and thread as well. Inside this analysis, there is the tire slip angle value, that is consequence of lateral forces acting over the tire. This characteristic is predicted in some cases, and evaluated on another ones. This paper brings to community another point of view of slip angle. We propose a mathematical model that describes a constraint linking slip angles and steering angle, in the way that makes the vehicle turns. We present the kinematic model that makes all three angles compatibles each other, function of the radius' corner.

Stability of motion, turnability, mobility and fuel consumption of all-wheel drive terrain vehicles strongly depends on engine power distribution among the front and rear driving axles and then between the left and right wheels of each axle. This paper considers kinematic discrepancy, which characterizes the difference of the theoretical velocities of the front and rear wheels, as the main factor that influences power distribution among the driving axles/wheels of vehicles with positively locked front and rear axles. The paper presents a new algorithm which enables minimization of the kinematic discrepancy factor for the improvement of AWD terrain vehicle dynamics while keeping up with minimal power losses for tire slip. Three control modes associated with gear ratio control of the front and rear driving axles are derived to provide the required change in kinematic discrepancy. Computer simulation results are presented for different scenarios of terrain and road conditions.

One method of reducing the number and/or severity of vehicle crashes is to warn the driver of a potential crash. The theory is that there will be driving conditions in which the drivers are unaware of a potential crash and a warning system will allow them to, in some manner, avoid the accident or reduce the severity. In an attempt to develop an analytical understanding of Forward Collision Warning systems (FCW) for frontal impacts a 2-d mathematical/kinematic model representing a set of pre-crash vehicle dynamic maneuvers has been built. Different driving scenarios are studied to explore the potential improvement of warning algorithms in terms of headway reduction and minimization of false alarm rates. The results agree with the field data. NHTSA's new NCAP active safety criteria are evaluated using the model. The result from the analysis indicates that the NHTSA criteria may drive higher false alarm rates. Opportunities of minimizing false positive rates are discussed.