DE10229520A1 - Controlling vehicle processes, involves copying output parameter of at least one faster task program at start of this program if such an output parameter provided for both faster and slower programs - Google Patents

Abstract

The method involves using at least one faster and at least one slower task program with at least one process parameter in both programs and copying it from one memory area to another. An output parameter of the at least one slower program is copied at the end of at least one faster program and/or an output parameter of the at least one faster program is copied at the start of this program if such an output parameter is provided for both programs. Independent claims are also included for the following: (a) an operating system for controlling processes in vehicles (b) and a device with at least one memory for storing processes in a vehicle.

Description

State of the art

The invention relates to a method and a device and a corresponding operating system for Control of operations for a vehicle according to the generic terms of independent claims.

Operating processes in the vehicle are based on operating systems as the basis for executing control processes. In operating systems, especially real-time operating systems, such as z. B. are used in embedded systems in the automotive industry, the functions are often divided into several tasks, so-called task programs with different sampling times, so that time-critical parts can be calculated more often than less time-critical algorithms or programs or program parts. The operating system usually ensures data consistency. For example, copies of sizes that are accessed in several tasks are created at suitable times so that, for. B. in slow task programs or tasks between two accesses, the value does not change because the size is written in a faster task. This is for example in the EP 0 799 441 B1 shown.

In control engineering applications, such as B. in the driving dynamics control system ESP or as part of a Engine and transmission control, etc. is not enough, just data consistency, guarantee as described above. It is also important here that the copies of sizes the can be used in different tasks or task programs be created at specific times to be an equidistant Ensure scanning; d. H. the copies should always be as similar as possible time intervals to be created. Currently available Real time operating systems for embedded systems do not contain any so-called embedded systems Mechanisms.

So the task for control engineering Applications in the vehicle in a simple manner an equidistant in time Allow scanning. As a further task, particularly time-critical processes should also be sufficient considered can be.

Advantages of invention

Through the presented below Invention ensures that so-called embedded systems embedded systems with real-time operating system all sizes that in several task programs or tasks, with different Sampling times required become, at equal intervals, that is, equidistant between the task programs (Tasks) are copied to ensure data consistency, i.e. a unwanted overwriting of these sizes prevented becomes.

For control engineering applications is the time equidistant Sampling is often essential to calculations such as integration or Differentiation of signals to carry out without increased computing effort. This increased Computational effort would arise thereby, for example, by including the time information provided per signal.

Thus advantageously takes place a method and an apparatus and an operating system for Control of operations in a vehicle use, the processes being carried out by at least one faster one Task program and at least a slower task program are controlled and at least one output variable in the at least one faster task program and at least a slower one Task program is used, this from a memory area is copied into another memory area and the one output size for the at least a slower task program at the end of at least a faster one Task program is copied and / or an output size for the least a faster task programs at the start of at least one faster task program is copied if such an output size is appropriate for both Task programs are provided.

Everyone is expedient for this Task program has its own memory area and / or one each internal counter assigned.

The task programs also receive appropriately different priority according to the maximum duration of each task program.

The advantage is that after expiration of the slowest task program all counters at the beginning of the fastest Task program are reset, and each sequence of each task program is counted in the respective counter.

It is expedient to use a Query the meter readings at the beginning and at least one copy routine is called at the end of each task program, advantageously using a rule, in particular a table specifies which output size goes where is copied, i.e. which copy routines are called in each case.

In an advantageous embodiment is additional at least one status bit is provided, which is characterized by the slower Task program can be set, the faster if the status bit is set Task program directly on the output size so the original of the output size and not accesses the copy of the slower task just before this copy is made.

The status bit is expedient in this particular embodiment of the invention then reset when the corresponding output size of the slower task program is copied.

Other advantages and beneficial Refinements result from the description and the features of claims.

drawing

The invention is further illustrated of the figures shown in the drawing.

This shows 1 is a schematic representation of a controller in a vehicle with different task programs.

2 illustrates the method according to the invention using three task programs.

In 3 a table is given as a regulation for controlling the copying or transfer routines.

4 shows a special embodiment of the invention in which a status bit is set and reset.

description of the embodiments

1 shows a control 100 with inputs or input variables E and outputs or output variables A. The control can 100 be constructed as a singular control unit as well as a network of bus-connected control units.

The controller can still be in particular at least one bus system with other controls as well with sensors or actuators to control processes in be connected to a vehicle. Thereby of sensors, further controls Input variables supplied or actuator technology are combined in a block and marked with E.

The one through the controller 100 Output variables, for example responses to other controls or sensors, and actuators, in particular control variables, are combined as output variables A in a block. In the controller, in particular in the context of an operating system, three task programs, so-called tasks T5, T10 and T20, are considered. These can depend on the structure of the control 100 be present in one control unit or in several control units. It is even conceivable to distribute a single task over several control units. The same applies to the memory areas SB5, SB10 and SB20 assigned to the individual task programs or tasks. These are each assigned to a task, but can be distributed both in the same control unit or in the same memory or in different memories and / or different control units, so to speak as virtual memory.

The individual task programs or tasks T5, T10 and T20 are assigned counters Z5, Z10 and Z20, which can be implemented in hardware or software on the one hand and as an internal counter of the corresponding task. The individual task programs or tasks thereby also variables and sizes among each other, especially in the frame exchange the individual program tasks. Because these variables or Sizes in general have their starting points in and from a particular task output, either as output variable A or to other tasks these sizes further commonly referred to as output sizes.

In 2 the procedure for three task programs or three tasks T5, T10 and T20 is shown as an example. To ensure data consistency, it is necessary that the variables, hereinafter referred to as output variables, which are used in several tasks or task programs, are normally also stored several times in the memory, for example a RAM memory. I.e. the memory here is designed as RAM, for example, any other form of memory known to the person skilled in the art, as mentioned above, can also be used virtually distributed in a network.

These sizes, these output sizes are not stored several times in memory, then it can e.g. B. occur that sizes be written in a fast task and in a slower one Task can be read while change the runtime of the slower task. That means everyone Task program, so each task advantageously has its own Has storage area SB. At the appropriate times, the Variables, so here the output sizes are copied over if these output sizes for several Task programs are provided. This could, for. B. a size that in task T10, for example, a 10 ms task, i.e. with a maximum runtime of 10 ms, is calculated to task T5, that is for example, a task with a maximum runtime of 5 ms and that to task T5, which after completion of the corresponding 10 ms task T10 next starts. this leads to then, however, too non-equidistant Sampling, since in the example task T10, i.e. the 10 ms task, is different can have long terms. That is why the copy of the variable generated at fixed times, with the aim of being generally equidistant Ensure scans.

To do this starts in 2 First the T5 task, in this example 5 ms, since in this example it has the higher priority over slower tasks, i.e. here T10 and T20. I.e. A priority is expediently introduced here depending on the maximum runtime or the speed of the task program. At the end of the T5 task, the interface sizes, ie in this case the output sizes A5-0 calculated in the T5 task T5-0, are copied to the memory area SB10 of task T10 or SB20 of task T20.

After task T5-0 ends the 10 ms task T10-0. This task T10-0 is carried out by the next 5 ms task T5-1 due to the higher priority interrupted. At the end of task T10-0, output sizes A10-0 task T10-0 to the respective memory areas of task T20, So copied to SB20, but not to the memory area of the faster T5 task T5-2. Would this copying of the output sizes A10-0 on SB5, so for T5-2 performed, then task T5-2 would have output size A10-0 in the example Task T10-0 and the next one 5 ms task T5-3 the results of T10-1 because the second 10 ms task fortuitously a little earlier will end as the first. The principle of equidistant sampling would be in this case injured. Because of this, the copying routine is slow to a faster task always at the beginning of the faster task carried out, d. H. At the start of task T5-2, output sizes A10-0 are copied from T10-0 and at the start of task T5-4 those of T10-1 and T20-0.

I.e. to ensure equidistant scanning So the copying rules are that the output sizes for slower ones Tasks are copied at the end of the faster task and output sizes for faster Tasks are copied at the beginning of the faster task.

To control the copying routines, i.e. the regulation of which output size or which output sizes are copied from which task to which other task, the tasks, in this case T5, T10 and T20, each have an internal counter or a counter is assigned to them, in accordance with Z5, Z10 and Z20 in 1 , Here in the example, after 20 ms, all counters are set to zero at the start of a T5 task or reset to the initial value. At the end of each task, the corresponding counter is increased by one. By querying the counter readings at the beginning and at the end of each task, you can then control which copy routines are called up.

This is, for example, based on tables 3 represented. The copying instructions for the T5 counter Z5 and the T10 counter Z10 are shown in tables 300 and 301 depending on the counter reading. So at T5 counter reading, i.e. Z5 counter reading 0 and at the beginning of task T5 the output sizes are copied from T10 to T5 and from T20 to T5 and at the end of the T5 task the output sizes from T5 to T10 and T5 to T20. The other copying processes are also examples, as just described, the tables 300 and 301 refer to.

At the end of T10-1, output sizes A10-1 are transferred to T5-4 as described. The sizes A20-0 are also transferred to T5-4 and T10-2 at the end of task T20-0. Finally, A5-4 is copied from T5-4 to T10-2, this being based on the in 3 shown regulations is controlled.

This is for control engineering applications an equidistant in time Sampling without including the time information supplied, i.e. without increased Computing effort very easy to do.

In some time critical cases shown in 4 , you cannot wait in a faster task until the copy of an output variable from a slower task is available, but you want to access the result of a calculation as soon as it is available, i.e. the original of the output variable, possibly without the equidistant sampling.

In this special embodiment the invention just a short-term abolition of the equidistant Sampling without total the equidistant Hurting or questioning scanning sets the slower one Task a status bit as soon as one or more quantities are fully calculated were. If the status bit is set, the faster task can open directly access the original of the variable or the output size.

In the subsequent standard copying process the status bit is then reset. Well, so with reset Status bit may only be the copy of the output size just created in the faster task can be used. Between setting the status bit and execution the output routine must then no longer be changed in the copy routine.

So when the status bit is set the original is valid, because it was calculated in the slower task and before it expired the task no longer changed becomes. If the status bit is not set, only the copy is valid.

This chronological order is in 4 shown. In the example, task T5-1 has to work with the copy of the output size, because the original size in task 1010 T10-0 has not yet been calculated and may currently have invalid values. The status bit is only set and the original AO10-0 can be accessed only when the result is available, i.e. the original of output variable AO10-0 has been calculated. The copy of output size A10-0 is then copied from T10-0 to task T5-2.

With this copying process is now the status bit is reset. The same applies to the next Size AO10-1, So the original of the task T10-1 at the time this was calculated or made available. Again, this can be done Originally accessed and the status bit is set again. Only when the copy A10-1 for T5-4 is subsequently created then the status bit is reset. The same applies to AO10-2.

Tasks T5-2 and T5-4 use or calculate with the copy A10-0 or A10-1 just created, as provided in the invention and not with the original. Task T5-3 has the option of using this additional option of the status bit to continue calculating with the fully calculated original size AO10-1 from the 10 ms task T10-1. This also applies to task T5-5 with the original size AO10-2 of task T10-2.

The invention thus enables in a simple manner an equidistant Scanning, in a special embodiment additionally in particularly time-critical situations through an additional mechanism without loss of security the mechanism of equidistant sampling in the short term can be circumvented without this basic mechanism according to the invention the equidistant To prove sampling with errors. I.e. it usually becomes the equidistant Sampling guaranteed, with time-critical exceptions high security taken into account can be.

Claims (11)

Method for controlling processes in a vehicle, the processes being controlled by at least one faster task program and at least one slower task program, at least one output variable being used in the at least one faster task program and the at least one slower task program, and for this purpose from a memory area into one is copied to another memory area, characterized in that an output variable for the at least one slower task program is copied at the end of the at least one faster task program and / or an output variable for the at least one faster task program is copied at the beginning of the at least one faster task program, if such Output size is provided for both task programs. A method according to claim 1, characterized in that each Task program is assigned its own memory area. A method according to claim 1, characterized in that each An internal counter is assigned to each task program. A method according to claim 1, characterized in that the Task programs have different priorities depending on a maximum run time of each Possess task program. A method according to claim 3, characterized in that after The slowest task program runs all counters at the start of the fastest task program reset and each sequence of each task program is counted in the respective counter. A method according to claim 5, characterized in that based on a query of the meter readings at the beginning and at the end of each task program at least one copy routine is called. A method according to claim 6, characterized in that based on a regulation, in particular based on a table which output size goes where is copied, i.e. which copy routines are called in each case. A method according to claim 1, characterized in that at least a status bit can be set by the slower task program and that the faster task program when the status bit is set directly to the output size of the slower Accesses the task program before it is copied. A method according to claim 8, characterized in that then, if the output size of the slower Task program is copied, the status bit reset becomes. Operating system for controlling processes in a vehicle, at which by execution task programs of at least one of the procedural steps according to one of the claims 1 to 9 executed becomes. Device with at least one memory for controlling operations in a vehicle, wherein first means are contained which the operations through at least a faster task program and at least control a slower task program, with at least one Output size in the at least a faster task program and at least a slower task program is used by one Memory area of the memory copied to another memory area is characterized in that second means are included, which is an output variable for the at least a slower task program at the end of at least a faster one Copy task program and / or an output size for the at least one faster task program at the start of at least one faster Copy task program if such an output size for both task programs is provided.