EST117B－降低單H操縱桿手動(dòng)變速器同步故障的ZF變速器控制單元

Dipl.－Ing.（BA）Sabrina Broschat，ZF Friedrichshafen AG Dipl.－Ing.（FH），Dipl.－Math.（FH）Timo－Bastian Konkol，ZF Friedrichshafen AG

目前很多OEM決定將雙H桿操縱系統(tǒng)改成為單H桿操縱系統(tǒng)以應(yīng)用到手動(dòng)變速器上（例如ZF公司的ECOSPLIT或ZF ECOMID）。

其背后的原因是為了減少換檔桿自身及在駕駛室中移動(dòng)所需的空間，尤其是改善換檔的人機(jī)工程（見圖1和圖2）。

同時(shí)新方法將增加無意識(shí)的換檔過錯(cuò)，這將導(dǎo)致超載，最壞情況下會(huì)導(dǎo)致變速器同步器的損壞。因此必須引入機(jī)械保護(hù)機(jī)構(gòu)。

圖1 雙H操縱桿式Fig.1 Double－H Shift Pattern

1 Introduction

Currently many OEMs2decide to change from double－H to single－H gear shift systems regarding their applications with manual shifted range gearboxes（for example ZF ECOSPLIT or ZF ECOMID）.

The reasons behind this decision are a reduced amount of space needed for the shift knob and its movement within the driver’s cabin and especially improved shift ergonomics（see Figure1/Figure2）.

Simultaneously this new approach may increase the probability of unintended miss－shiftings that can lead to overload or in worst case to destruction of the synchro－units within the gearbox.Therefore the need to introduce a defined protection－mechanism arises.

ZF developed a system that－based on the com－bination of a TCU，a valve box and the pneumatical connection to the gearbox－is able to support avoidance of miss－shiftings depending on the driving situation of the vehicle.

圖2 單H操縱桿式Fig.2 Single－H Shift Pattern

ZF公司開發(fā)的系統(tǒng)與TCU相聯(lián)，由一個(gè)閥室和連接在變速器上的氣動(dòng)管路等組成，它能夠根據(jù)車輛的行駛狀況避免換檔過錯(cuò)。

根據(jù)若干個(gè)安裝在變速器上的位置傳感器，將輸入軸和輸出軸的轉(zhuǎn)速和信號(hào)差與駕駛員需求相連，EST117B系統(tǒng)能夠允許或禁止變速器的換檔動(dòng)作。這意味著通過定義一個(gè)或多個(gè)電磁閥的接通與斷開實(shí)現(xiàn)檔位范圍切換（1－4檔或5－8檔）和掛入副變速器或者禁止換檔過程的進(jìn)行。

另外，當(dāng)車速過高時(shí)系統(tǒng)將激活一個(gè)閥門以鎖定門電路避免誤選某一門電路。這時(shí)駕駛員將立即從操縱桿上獲得一個(gè)觸覺反饋。如果系統(tǒng)準(zhǔn)備禁止換檔的話，可選擇激活蜂鳴器。

為了滿足中國、巴西、俄羅斯和印度等潛在市場的需求，ZF公司正設(shè)法找到成本和技術(shù)方面的平衡點(diǎn)。

因此，一方面信號(hào)界面很?。ㄒ妶D6）硬件成本（包括TCU）便宜。另一方面TCU軟件提供一個(gè)完整的系統(tǒng)診斷、與CAN－bus（SAE J1939）的連接和UDS診斷協(xié)議。其中最新、最尖端的ZF軟件部分被用來產(chǎn)生協(xié)同作用和提供現(xiàn)代化技術(shù)。

2 單H操縱桿手動(dòng)變速器

手動(dòng)切換檔位范圍變速器（ZF－Ecomid和ZFEcosplit）采用了兩種不同的換檔模式：

· 雙H操縱桿式（圖1）

· 單H操縱桿式（圖2）

雙H操縱桿模式被用于傳統(tǒng)的變速器換檔系統(tǒng)。包括1－4檔的低速檔和5－8檔的高速檔排列在一條線上。

如此排列需要一個(gè)長的選擇行程?，F(xiàn)在這種特性不能滿足所有用戶的要求。越來越多的車輛制造商正在把雙H操縱桿改為單H操縱桿系統(tǒng)。

單H操縱桿模式改善了換檔人機(jī)工程，并且在駕駛室中的安裝空間小。理由是低檔組（GPL）和高檔組（GPH）的換檔模式重疊。

除了檔位切換機(jī)構(gòu)之外，ZF Ecosplit可增加一個(gè)與換檔模式無關(guān)的副變速器（GVL/GVH）。該副變速器被用來細(xì)分原有的8檔以實(shí)現(xiàn)16個(gè)級(jí)差接近的前進(jìn)檔。它由操縱手柄上的預(yù)選開關(guān)激活。通常，這些變速器都安裝稱作為ZF Servoshift的氣動(dòng)輔助換檔裝置。

為確保單H桿變速器的順序換檔的舒適性和保護(hù)同步器免于誤換檔，必須增加一些輔助裝置。其中之一是被稱為E13模塊（圖3）的閥門閉鎖器.E13模塊由5個(gè)電磁閥組成，用來激活檔位切換、副變速器（ZF－Ecosplit）、伺服動(dòng)力和若干保護(hù)功能。

Based on several position switches within the gearbox，the input－shaft－and the output－shaft－revolution speed and different signals connected to the driver’s demand，the EST117Bsystem is able to release or inhibit the shifting of single gearbox components.In detail this means that by defined（de－）activation of one or more solenoid valves the shifting of the range（gears 1to 4or gears 5to 8）and the splitter（splitted gears）is allowed and executed or that this shift－process is prohibited and therefore will not be performed.

Additionally this system is able to activate a valve to lock single gates to avoid selecting agate if the current vehicle speed is too high.In this case the driver gets immediate haptic feedback from the shift knob.Optionally a warning buzzer can be activated if the system intends to prohibit an intended gear shift.

To satisfy the requirements of emerging markets like China，Brasil，Russia and India，ZF tried to find the correct balance between costs and stateof－the－art techniques and helpful features.

Therefore on one hand the signal interface is small（see Figure6）and the hardware costs（including the TCU）are cheap.On the other hand the TCU software provides a complete diagnostic of the system，a connection to the CAN－bus（SAE J1939）and the diagnostic protocol UDS on CAN.Internally the newest and most sophisticated ZF software components were integrated to use synergy effects and to offer state－of－the－art technology.

2 Manual Transmissions with Single－H

The manual range change transmissions（ZFEcomid［Figure5］and ZF－Ecosplit［Figure4］）are available with two possible gearshift patterns：

· Double－H ［Figure1］

·Single－H ［Figure2］

The Double－H shift pattern represents the traditional gearshift system.The low range group （GPL），which comprises gear 1to 4，and the high range group（GPH），with gear 5to 8，are placed in line.

圖3 單H桿換檔轉(zhuǎn)塔Fig.3 Single－H shift turret

圖4 單H桿Ecosplit 4變速器Fig.4 Ecosplit 4with Single－H

圖5 帶緩速器的單H桿Ecomid變速器Fig.5 Ecomid with Single－H and Intarder

This positioning requires a long select travel.Nowadays this characteristic does not fulfil the requirements of each customer.Increasingly the vehicle manufacturers replace the Double－H gearshift system by a Single－H gearshift system.

The Single－H shift pattern improves the ergonomic of shifting and needs less installation space in the driver’s cab.Reason is the superimposition of shift patterns of low range group（GPL）and high range group（GPH）.

Besides the range change group an additional splitter group （GVL/GVH）is available for ZFEcosplit transmissions which is independent of the gearshift pattern.The splitter group can be used to sub－divide the 8speeds once again to a total of 16 closely－stepped forward speeds.It is actuated by a pre－select switch on the shift knob.Generally these transmissions are equipped with a pneumatic shift assistance known as ZF Servoshift.

To ensure a comfortable shift sequence of manual transmissions with Single－H and to protect the synchronizers against miss－shiftings several additional components are required.One component is a valve block，called E13module（Figure3）.The E13module contains five solenoid valves，which are used for the actuation of range change group，splitter group （ZF－Ecosplit），servo power and several protection functionalities.

3 EST117B－Protection Functions

The transition from Double－H to Single－H gearshift system may increase the risk of unintended miss－shiftings by the driver.

For instance if the driver intends to shift from 4th gear into 5th gear，the range change group has to be changed from GPL to GPH.But if the driver forgets to operate the GP preselection switch，which is placed on the shift knob，no range change will take place.The transmission stays in GPL and without protection functions4this shifting procedure would lead to a miss－shifting from 4th gear into 1st gear（instead of intended 5th gear）.Thereby the synchronizer might be damaged by too high friction speed，and even worse overspeeds of the engine and clutch disk could occur.

To avoid these unintended miss－shiftings ZF provides special protection functions.

Gate interlock：Above defined output shaft speed of transmission the access into gate 1/2（GPL）or gate 5/6 （GPH）is not allowed and therefore locked.

Range interlock：Above defined output shaft speed of transmission the access into low range group（GPL）is not allowed and therefore locked.

Servo air cut off：As long as the clutch pedal is not pressed completely the air support for Servoshift is deactivated.

3 EST117B－保護(hù)功能

換檔系統(tǒng)從雙H桿轉(zhuǎn)化為單H桿將增加駕駛員的無意識(shí)換檔錯(cuò)誤。

例如如果駕駛員決定從4檔切換到5檔，動(dòng)力傳遞路線將從GPL轉(zhuǎn)換到GPH。但是如果駕駛員忘記操作安裝在換檔手柄上的GP預(yù)選開關(guān)，將不會(huì)出現(xiàn)檔位范圍的切換。變速器仍然處于GPL工作狀態(tài)，如果沒有保護(hù)功能的話這次換檔將導(dǎo)致從4檔到1檔（而不是5檔）的錯(cuò)誤換檔。因而同步器由于過高的摩擦速度而受損，甚至?xí)霈F(xiàn)更嚴(yán)重的發(fā)動(dòng)機(jī)和離合器從動(dòng)盤的超速。

為避免這些無意識(shí)的換檔錯(cuò)誤，ZF提供了特殊的保護(hù)功能。

門互鎖：當(dāng)被定義的變速器輸出軸轉(zhuǎn)速超出時(shí)，進(jìn)入門1/2（GPL）或門5/6（GPH）的通道被禁止因而閉鎖。

檔位范圍互鎖：當(dāng)被定義的變速器輸出軸轉(zhuǎn)速超出時(shí)，進(jìn)入低檔范圍（GPL）被禁止因而閉鎖。

伺服空氣切斷：一旦離合器踏板沒有完全踩下，伺服換檔的氣壓助力不起作用。

4 EST117B－界面示意圖

下圖（圖6）給出了EST117B的界面示意圖。

4 EST117B－Interfaces Diagram

The following picture（Figure6）shows the interface diagram of the EST117Bin the current available configuration.

圖6 界面示意圖Fig.6 Interface diagram

5 117B－軟件

最重要的目標(biāo)之一是必須開發(fā)一套在新興市

場例如金磚四國具有競爭力的系統(tǒng)。因此其特殊需要在于系統(tǒng)耐用性和技術(shù)簡單化方面的提升：與歐洲相比，由于缺乏足夠的維修網(wǎng)絡(luò)和各自不同的地形而需要高可靠性的車輛。同時(shí)所提供的功能將能夠直接支持駕駛員和系統(tǒng)自身，并控制在一個(gè)可接受的價(jià)格上。

這些需求直接影響系統(tǒng)的構(gòu)建。以下的表格（表1）給出了所需的信號(hào)和責(zé)任方：

表1 車輛功能界面Table1 Vehicle functional interface

信號(hào)界面簡單易懂并且能夠?qū)⑽锢硇盘?hào)直接與TCU相聯(lián)或通報(bào)給SAE J1939CAN總線（見圖6）。

5 EST117B－Software

One of the most important targets was to develop a system that is able to compete in emerging markets like the BRIC5－states.Therefore specific requests to system roughness and technical simplicity arise：compared with Europe there is no dense service net available and geographical respective geopolitical reasons require high vehicle availability.Simultaneously the provided functionality shall directly support the driver and the system itself and is available at an acceptable price.

These requests directly influence the system architecture.The following table（Table1 ）displays the needed signals and the current responsible party：

The signal interface is straightforward and can be provided either by physical signals directly connected to the TCU or by messages on SAE J1939 CAN bus（see also Figure6）.

The small amount of necessary signals makes it easy for an OEM to integrate this system into his vehicle.For ZF it means－combined with the request formulated in the beginning of this chapter－to develop a high－sophisticated diagnosis that on the one hand recognizes each possible failure（and therefore protects the driver and the system）but on the other hand ensures a high vehicle availability.

Figure7shows the software architecture of this system.

Below a short description of the visible design elements（Table2 ）：

圖7 EST177B軟件體系結(jié)構(gòu)Fig.7 Software Architecture EST117B

所需信號(hào)最少使得OEM能夠很方便地將其集成到整車系統(tǒng)中。對(duì)于ZF而言，這意味著能夠與本節(jié)開始時(shí)所闡述的需求結(jié)合起來開發(fā)出一套高度復(fù)雜的診斷系統(tǒng)，一方面能夠識(shí)別各種可能的故障（因而能夠保護(hù)駕駛員和系統(tǒng)），另一方面提高了車輛的可用性。

表2 部件功能Table2 Design Elements

雖然該系統(tǒng)的安全等級(jí)（根據(jù)IEC61508）是SIL0，其軟件結(jié)構(gòu)接近于軟件相關(guān)系統(tǒng)。診斷監(jiān)控器的軟件適用于如何輸入信號(hào)。該軟件的任務(wù)是對(duì)指定的信號(hào)進(jìn)行真實(shí)性檢驗(yàn)。該項(xiàng)檢驗(yàn)基于冗余信號(hào)或所定義的似然性邏輯。另外，這些診斷監(jiān)控器與禁止矩陣相聯(lián)以解決信號(hào)交叉存取的問題。保護(hù)功能軟件的輸出結(jié)論作為激活閥門的一個(gè)要求。該項(xiàng)激活受控于被稱為替換功能的附加軟件。根據(jù)保護(hù)功能和似然性功能作出評(píng)價(jià)決定是否激活，這成為核心軟件的一部分。

Despite the fact that the safety classification（according to IEC61508）for this system resulted in SIL0，the software is structured close to safety－relevant systems.A diagnostic monitor software component exists for every incoming signal.Task of this component is to perform a plausibility check for its assigned signal.This check is executed either based on a redundant signal or on defined plausibility logic.Additionally these diagnostic monitors are connected within a prohibition matrix to solve the problem of signal interleaving.The resulting output of the protection function software component is a request to activate valves of the valve module.The activation is checked by an additional software unit called substitute functions.This unit evaluates－based on the results of the protection and plausibility functions－if a valve is allowed to become active or not and therefore becomes one of the central software parts.

The combination of ZF Errorhandler and the diagnostic protocol UDS6（or diagnostic messages according SAE J1939－73）allows the OEM to communicate directly with the TCU to gather deeper informations about emerged errors.

Substitute functions（that means：the reaction of the system in case of a failure）try to find the balance between a high vehicle availability and the possibility to protect the system of damages.

Due to the high flexibility of the implemented software architecture customisation to new customer requests are possible.Currently the software recognizes 45different errors，supports 11diagnostic monitors and 10different substitute functions that are also evaluated by means of two different prohibition matrices.

As mentioned above，regarding the protection functions a special approach was taken（also mentioned above）.In the last years a new software creation process definition called Model Based Software Engineering became more and more important to current projects.

In this project the MBSE process was used to implement the protection functions.Reasons why it was used in EST117B：

ZF Errorhandler和UDS診斷協(xié)議（或根據(jù)SAE J1939－73診斷信息）的結(jié)合可使OEM直接和TCU通訊，從而獲得有關(guān)故障的深層次信息。

替換功能（出現(xiàn)故障時(shí)系統(tǒng)的反應(yīng)）則試圖在車輛高可用性和預(yù)防系統(tǒng)受損方面找到一個(gè)平衡。

由于軟件結(jié)構(gòu)編輯模式的高度靈活性，使得更新用戶要求變成可能。目前軟件能夠識(shí)別45種不同的錯(cuò)誤、支持11種診斷模式和10種不同的替換功能并能根據(jù)兩種不同的禁止矩陣作出評(píng)價(jià)。

正如上述所及，對(duì)于保護(hù)功能而言具有一個(gè)特殊的途徑。去年新開發(fā)的Model Based Software Engineering軟件對(duì)于目前方案正變得越來越重要。

在該方案中，MBSE程序被用來實(shí)現(xiàn)保護(hù)功能。其采用EST117B的理由如下：

·通用開發(fā)語言使得功能開發(fā)者和軟件開發(fā)者能夠在公共平臺(tái)上討論相同的問題。

·Common development language that allows both developer of functions and software developer to discuss about the same topic on a common base

·Possibility for rapid prototyping to evaluate new functionalities directly in a SiL7simulation environment

· Flexibility to add new customer－related requests into the protection functions

The implemented model currently consists of approximately 1800modelling elements.The following picture（Figure8）shows an excerpt（functional layer）of the MBSE8－model.

6 Summary

This ZF development proved that all requirements for emerging markets（like robustness，flexibility and price awareness）can be fulfilled.

圖8 EST117B功能模塊Fig.8 Excerpt of EST117Bfunctional model

· 能夠利用快速原型直接在SiL仿真環(huán)境中評(píng)價(jià)新功能。

·其靈活性使得能夠在保護(hù)功能中添加用戶相關(guān)的需求。

目前執(zhí)行模塊包含有約1800個(gè)模塊單元。下圖（圖8）在功能層面上摘錄了MBSE模塊。

6 結(jié)論

ZF公司的研發(fā)成果被證明在耐用性、靈活性和成本方面能夠滿足新興市場之需求。在經(jīng)歷了一年的耐久性試驗(yàn)和對(duì)EST117B系統(tǒng)稍作優(yōu)化后，將于2011年向優(yōu)化推出系列產(chǎn)品。

With the completion of the one year lasting field test，which included also slight optimizations for the EST117Bsystem，the series start－up of the system lead customer will be launched in July 2011．

iOriginal Equipment Manufacturer

2Original Equipment Manufacturer

3Transmission Control Unit

4Corresponding to described example the gate interlock would avoid miss－shifting into 1st gear

5BRIC：Brasil，Russia，India，China

6Unified diagnostic services（ISO 14229－1）

7Software in the Loop：closed simulation loop that is driven by a vehicle/track model

8Model Based Software Engineering：model driven software development including autocode－generation