Konrad Wöllhaf

BaSiP : Batch process simulation with dynamically reconfigured process dynamics

Abstract Recipe-driven automatic production is widely used to reduce the load on the operators and to allow them to focus on the high level tasks of assignment of equipment, sequencing, and scheduling. Simulation can support these functions by answering if .. then questions, finding bottlenecks or underused equipment, testing of recipes, detecting illegal or dangerous operations. The major challenge of the simulation of batch plants is the hybrid nature of the system, combined with frequent changes of the structure of the system, which in our opinion necessitates a dynamic configuration of the simulation model during the simulation run. This is realized in the program BaSiP which is designed to simulate the operation of recipe-driven multipurpose batch plants.

Verification of Recipe-Based Control Procedures by Means of Predicate/Transition Nets

The paper presents a method for the verification of control procedures which are based on so-called recipes. The concept of recipes is widely used in the control of multipurpose chemical batch plants which are very similar to Flexible Manufacturing Systems.

Dynamic simulation of batch plants

Abstract This contribution describes the structure of a simulation system for the operation of flexible batch plants which includes both continuous and discrete dynamics. The structure is closely related to the standards for recipe-controlled operation of batch plants which are used in the automation of batch plants by all major suppliers of process control systems.

HYBRID SIMULATION OF FLEXIBLE BATCH PLANTS

Abstract In this contribution the structure of a simulation system for flexible batch plant operation, which tracks the complete state of the plant and includes both continuous and discrete dynamics, is described. The system consists of two parts, the batch plant and its operational functionality and the recipe, which describes the production process. The object-oriented model of the production process is based on the concept of recipe controlled operation.

Object-oriented modelling and simulation of batch plants

In this paper, the modelling and simulation of recipe driven multipurpose chemical or biochemical plants using an object oriented approach is described. A data model is presented which enables the description of all important aspects of batch plants: the model of the plant (reactors, tanks, pipes, separation units etc.), the batches of material and the dynamics of their transformation, and the recipe driven sequential production process. Batch plants are complex hybrid systems (Cellier et al. (1993), Clark and Joglekar (1992)) because many different components with associated continuous dynamics are involved, the production sequence is event-driven, continuous and discrete state variables must be used to describe the production process, and the structure of the system and the number of state variables change over time.

Simulation of Robots with Flexible Links

Abstract Robots with flexible links are getting more important in industrial or space applications to improve the payload to deadweight ratio. The use of lightweight material and structural optimization in order to increase this ratio leads to constructions with flexible robot links and drives. This paper presents a new and comprehensive simulation tool for arbitrary combinations of rotational and prismatic joints, which can be used for development of robot systems, diagnostics and controller design. The simulation is based on a model which takes into account both rigid and flexible links and nonlinear effects in the drives of the joints such as friction, backlash, gear elasticity and the performance of the measuring devices. The kinematic description is based on the Denavit-Hartenberg formulation which has been modified for the description of flexible structures. The link flexibility is modeled by shape functions using the Ritz method and has been integrated in the well known effective recursive Luh-Walker-Paul algorithm for manipulator dynamics, which has been extended for flexible structures.