Control system for calculating parameter control values in repetitive control processes
First Claim
1. In a control system for calculating control parameter values for repetitive controlled processes in a motor vehicle, including at least one of ignition, fuel injection, and braking processes,said control system havingat least one microprocessor,a plurality of peripheral modules,a plurality of sensors measuring respective operating parameters of said controlled processes for input to said plurality of peripheral modules,a serial data bus, interconnecting said at least one microprocessor and said plurality of peripheral modules, and carrying operating parameter values from said modules to said microprocessor, and parameter control values (Z, E, A, Dk) from said microprocessor to said modules, said parameter control values normally being cyclically occurring at periodic intervals,a method of operating said control system, whereinsaid at least one microprocessor (a) tests whether at least one predetermined operating parameter condition is satisfied by determining whether a current calculated control value (Dk1) of said predetermined operating parameter exceeds a previous calculated value (Dk0) of that parameter by more than a predetermined amount (dDk), and (b) inhibits transmission, on said serial data bus, of at least one of said cyclically occurring parameter control values when Dk1 does not exceed Dk0 by dDk, thereby reducing loading of said serial data bus.
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Abstract
It is known for a central electronic control unit in a motor vehicle to exchange data through a serial data bus with other control units, e.g. those for fuel injection, ignition timing, and braking. Prior art systems transmitted these data automatically, regardless of whether all these parameters were relevant to the actual operating state of the vehicle, thereby resulting in heavy loading of the serial bus. The present invention determines which parameters are irrelevant to the current operating state and suppresses transmission, or even calculation, of these irrelevant parameters.
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Citations
10 Claims
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1. In a control system for calculating control parameter values for repetitive controlled processes in a motor vehicle, including at least one of ignition, fuel injection, and braking processes,
said control system having at least one microprocessor, a plurality of peripheral modules, a plurality of sensors measuring respective operating parameters of said controlled processes for input to said plurality of peripheral modules, a serial data bus, interconnecting said at least one microprocessor and said plurality of peripheral modules, and carrying operating parameter values from said modules to said microprocessor, and parameter control values (Z, E, A, Dk) from said microprocessor to said modules, said parameter control values normally being cyclically occurring at periodic intervals, a method of operating said control system, wherein said at least one microprocessor (a) tests whether at least one predetermined operating parameter condition is satisfied by determining whether a current calculated control value (Dk1) of said predetermined operating parameter exceeds a previous calculated value (Dk0) of that parameter by more than a predetermined amount (dDk), and (b) inhibits transmission, on said serial data bus, of at least one of said cyclically occurring parameter control values when Dk1 does not exceed Dk0 by dDk, thereby reducing loading of said serial data bus.
Specification