Initial-value ordinary differential equation solution via variable order Adams method (SIVA/DIVA) package is collection of subroutines for solution of nonstiff ordinary differential equations. There are versions for single-precision and double-precision arithmetic. Requires fewer evaluations of derivatives than other variable-order Adams predictor/ corrector methods. Option for direct integration of second-order equations makes integration of trajectory problems significantly more efficient. Written in FORTRAN 77.

Solving Ordinary Differential Equations

The design of engine control systems has been traditionally carried out using a mix of heuristic techniques validated by simulation and prototyping using approximate average-value models. However, the ever increasing demands on passengers' comfort, safety, emissions, and fuel consumption imposed by car manufacturers and regulations call for more robust techniques and the use of cycle-accurate models. We argue that these models must be hybrid because of the combination of time-domain and event-based behaviors. We present a hybrid model of the engine in which both continuous and discrete time-domain as well as event-based phenomena are modeled in a separate but integrated manner. Based on this model, we formalize the specification of the overall engine control by defining a number of hybrid control problems. To cope with the difficulties arising in the design of hybrid controllers, a design methodology is proposed. This methodology consists of a relaxation of the hybrid problem by simplifying some of its components to obtain a solvable problem,and then deriving a solution to the original control problem by appropriately modifying the control law so obtained to take into consideration the original specifications and models. The effectiveness of this approach is illustrated on three challenging problems: fast force-transient control, cutoff control, and idle speed control.

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Automotive engine control and hybrid systems: challenges and opportunities

By using engine control during the gear shift, a manual transmission can be automated without using the clutch during the shift event. It is then important to minimize the total time needed for a gear shift, but when doing so driveline resonances may be excited. This in turn may lead to problems with disengaging the old gear and synchronizing speeds for engaging the new gear. Internal driveline torque control is a novel idea for handling resonances and increasing shift quality. By estimating the transmitted torque and controlling it to zero by engine control, the gear can systematically be disengaged with minimized driver disturbances and faster speed synchronization. Field trials show fast shifts to neutral gear, despite disturbances and driveline oscillations at the start of the gear shift. The control scheme is simple and robust against variations among different gears. Furthermore, damping of driveline resonances can be obtained with an observer in combination with a proportional integral derivative feedback structure, despite the higher order driveline system.

Gear shifting by engine control

New and exciting possibilities in vehicle control are revealed by the consideration of topography, for example through the combination of GPS and three-dimensional road maps How information about 

A Real-Time Fuel-Optimal Cruise Controller for Heavy Trucks using Road Topography Information

The problem addressed is how to drive a heavy truck over various road topographies such that the fuel consumption is minimized. Using a realistic model of a truck powertrain, an optimization proble ...

Explicit Fuel Optimal Speed Profiles for Heavy Trucks on a Set of Topographic Road Profiles

Process and control system for limiting the maximum braking effect which may be utilised from a retarder (16) (a hydrodynamic auxiliary brake) in an engine-driven vehicle (10), in which cooling of the hydraulic fluid heated by braking of the retarder is by coolant from the ordinary cooling system of the vehicle engine The maximum utilisable braking effect of the retarder (16) is controlled by at least the speed of the vehicle engine, with use for the purpose of an electrical control circuit which includes a control unit (26), which is connected to the retarder, and an engine speed sensor (36) which is connected to and conveys its output signal to the control unit (26), the output signal from which to the retarder (16) controls the maxium hydraulic pressure in the retarder The control circuit may also include a propeller shaft speed sensor (38) which is connected to the control unit (26), and/or a coolant temperature sensor (40)

Process and control system for limiting the braking effect which may be utilised from a hydrodynamic auxiliary brake in a motor vehicle

Controlling gear engagement and disengagement on heavy trucks for minimization of fuel consumption

By using engine controlled gear shifting, a manual transmissioncan be automated without using the clutch duringthe shift event.The main contribution of this paper is a novel extensionof the existin ...

Lars-Gunnar Hedström

Papers

Process and control system for limiting the braking effect which may be utilised from a hydrodynamic auxiliary brake in a motor vehicle

Controlling gear engagement and disengagement on heavy trucks for minimization of fuel consumption

Transmission-Torque Control for Gear Shifting with Engine Control