Vehicle Calibration Techniques Established and Substantiated for Motorcycles

Size: px

Start display at page:

Download "Vehicle Calibration Techniques Established and Substantiated for Motorcycles"

Shannon Wright
6 years ago
Views:

1 Technical paper Vehicle Calibration Techniques Established and Substantiated for Motorcycles モータサイクルに特化した車両適合手法の確立と実証 Satoru KANNO *1 Koichi TSUNOKAWA *1 Takashi SUDA *1 菅野寛角川浩一須田玄モータサイクル向け ECU は, 搭載性をよくするため小型化が求められ, また, 低価格な車両が多いため, その構成部品である ECU にも徹底したコスト削減が要求され, 内蔵 RAM 容量などは限界まで切り詰めた CPU が選定されている. 四輪車とは異なるこのような特徴が, 開発における車両適合にも影響を与えている. モータサイクルの適合では, 追加投資が必要な開発専用の ECU を用いるのではなく, 量産と同じ ECU で実現できることが検証の観点でも理想である. 本研究では, これらモータサイクル特有の課題を解決する手法として量産 ECU を用いた車両適合を確立した. 車両適合とは, 目標とする車両性能を得るためにエンジンベンチや走行テストで得られた計測データを解析しながら,ECU のエンジン制御データを PC のアプリケーションソフトウェアで調整する一連の作業である. 一般的な開発専用 ECU を用いる方法では,ECU の ROM 上の全制御データをコピーした RAM を直接編集することで達成している. これに対して本研究では, モータサイクル向け ECU の制御と同一の演算ロジックを適合用 PC アプリケーションソフトウェアに組み込んでいる.ECU ソフトウェアでは対象となるデータを調整する演算ロジックを切替え可能として組込み,PC アプリケーションソフトウェアからの指示に基づいて切替えが行われる. 適合時は PC アプリケーションソフトウェアで調整データの演算を行い, 結果を ECU 側へ送信し, エンジン制御データとして反映する. この一連の手順によって量産 ECU での車両適合を可能とし量産開発に適用して, その効果と有効性を実証した. Key Words Motorcycle, Vehicle calibration, Mass-production ECU, Measure and analyze INTRODUCTION From 2000 onward, superior fuel injection system components have been developed to meet emission regulations that apply to motorcycles suitable for wide engine rotational speed width and various environmental conditions such as high/ low temperature, wet, bad road and low quality fuel. Engine ECU is used to provide the optimal control signals to engine in order to enhance engine performance maximally across diverse environments [1-4]. Comparing with four-wheeled vehicle, productsize of motorcycle is more compact in general. Since load capacity limitation has influence on components layout which includes ECU, down-sizing of ECU also becomes essential requirement. On the other hand, functions of ECU increase explosively from a background like strengthening emission regulations until quite recently. Miniaturization and multi-function realized by high density mounting of ECU amounts to a factor of high cost. However, equivalent price to that of carburetor-equipped vehicle is required except Received 1 July 2013, Reprinted with permission, from SAE paper (JSAE paper # ). Copyright 2012 SAE International and SAE of Japan. Further use or distribution of this material is not permitted without permission from SAE International or SAE of Japan. *1 Development Department 5, Division 3, Tochigi R&D Center -27-

Vehicle Calibration Techniques Established and Substantiated for Motorcycles some large vehicles, and perfect cost reduction of component like ECU is requested certainly.

2 Vehicle Calibration Techniques Established and Substantiated for Motorcycles some large vehicles, and perfect cost reduction of component like ECU is requested certainly. To satisfy these conflicted requirements, capacity of ECU is reduced to limit in hardware development for fulfilling necessary performance as mass-production to obtain low cost. The different things from four-wheeled vehicle also affect vehicle calibration of motorcycles in development. Vehicle calibration is sequential procedure which adjusts control data of ECU by using PC application software to measure and analyze bench or vehicle test information repeatedly aiming to achieve target performance of vehicle as shown in Fig. 1. A typical technique for four-wheeled vehicle by means of dedicated development ECU is to reflect all control data deposited in ROM to RAM, and edit RAM data directly. Techniques utilizing dedicated development ECU have to use high performance CPU in which RAM capacity is large enough for all control data deposited in ROM to be reflected considering various models, leading to cost increase because of investment on expensive purchase. In the meanwhile, dedicated development ECU for common use is not superior to load capacity of motorcycles because form and size is not in conformity with vehicle layout. For these reasons, ECU developed for mass-production to be introduced in vehicle calibration for motorcycles is ideal considering investment reduction and vehicle load capacity. This research focused on establishment of two-way algorithm and communication protocol for ECU software and PC application software, in order to realize vehicle calibration on mass-production ECU in which capacity is truncated to a limit [5-6]. Fig. 2 illustrates difference in principle between techniques for motorcycles to be proposed in this paper and typical technique for four-wheeled vehicle. Typical technique for four-wheeled vehicle development Control design Fuel injection initially defined Write Dedicated development ECU Vehicle calibration Fuel injection temporarily fixed Write Mass-production ECU Proposed technique for motorcycle development Control design Fuel injection initially defined Write Dedicated development ECU Vehicle calibration Final confirmation on vehicle Chassis dynamo Final Fuel injection map data for mass production Final Fuel injection map data for mass production Measurement Fig. 2 Comparison between typical technique and proposed techniques TECHNIQUE ESTABLISHMENT Calibration Techniques concentrated in this paper Analysis Fig. 1 Vehicle calibration for motorcycles Subject, constraint and problems to be solved in this paper are clarified as follows. Subject establishing vehicle calibration techniques based on mass-production ECU -28-

3 Constraint specializing vehicle calibration on bench test (keeping steady state) Problems to be solved constructing a system that is not dependent upon a certain vehicle engine model constructing a system that can be achieved by using less ECU/PC resource constructing a system that acts in restraint of human error on vehicle calibration Fuel injection map adjustment is an example of fundamental vehicle calibration. Fuel adjustment is a repeating operation to approximate theoretical air fuel ratio by determining injection quantity, i.e., fuel injection correction for a certain vehicle condition referring to λ sensor value at this condition. Fuel injection map is a three dimensional data, in which a set of two dimensional data is given by indices to indicate vehicle condition and the third dimension data is defined as fuel injection quantity at lattice of indices. Sequential procedure for fuel injection map adjustment consists of, REFERENCE FUEL INJECTION QUANTITY CALCULATION TARGET FUEL INJECTION QUANTITY DECISION ADJUSTMENT PROPORTION CALCULATION ADJUSTMENT PROPORTION REFLECTION COMPLETED FUEL INJECTION MAP DATA REFLECTION, to be detailed latter. REFERENCE FUEL INJECTION QUANTITY CALCULATION Reference (or current) fuel injection quantity is calculated by fuel injection preserved in PC referring to parameters that indicates vehicle condition. When searching current fuel injection quantity, situation that parameters match with values of map indices is ideal, but it is hard to accomplish on vehicle. Thus, it is required that current fuel injection quantity can also be calculated as parameters deviating from lattice of indices. In order to satisfy this requirement, PC application software receives parameters from ECU, and searches neighbor indices in two dimensions respectively. Then, PC application software calculates positional relation of the parameters and neighbor 4 lattice points, and calculates injection quantity of corresponding parameters from injection quantity of corresponding 4 lattice points defined in fuel injection map proportionally. This calculation method is regarded as 4-point interpolation to be introduced. As shown in Fig. 3 and 4, indices of X-axis and Y-axis of three-dimensional fuel injection map denote as X i (i=1, 2,, m), Y j (j=1, 2,, n), respectively, Z (i, j) represents fuel injection quantity corresponding to map lattice point that consists of indices X i and Y j. Reference fuel injection quantity corresponding to arbitrary parameters X p, Y q (X i X p < X i+1, Y j Y q < Y j+1 ) is calculated by linear proportional interpolation from X-Z plane to Y-Z plane. Proportion of X_ratio, Y_ratio assigned to X p, Y q is calculated by using formula (1), (2). Y q Y Y 1 Y 2 Y j Y j+1 Y n Fig. 3 Yj+1 X 1 X 2 X i X i+1 X m Z (1, 1) Z (1, 2) Z (1, j) Z (1, j+1) Z (1, n) Z (2, 1) Z (2, 2) Z (2, j) Z (2, j+1) Z (2, n) Z (p, q) Z (i, 1) Z (i, 2) Z (i, j) Z (i, j+1) Z (i, n) Reference fuel injection quantity in cell consisted by neighbor 4 lattice points X p Z (i+1, 1) Z (i+1, 2) Z (i+1, j) Z (i+1, j+1) Z (i+1, n) Z (m, 1) Z (m, 2) Yq Yj Fig. 4 Z (i, j+1) Z Y_ratio Z (i, j) Z (p, j+1) X_ratio Z (p, j) Z (i+1, j+1) Z (i+1, j) Z(p, q) Xp 4-point interpolation method Xi Xi+1 Z (m, j) Z (m, j+1) Z (m, n) X -29-

4 Vehicle Calibration Techniques Established and Substantiated for Motorcycles X_ratio = (X p X i ) / (X i+1 X i ) (1) Y_ratio = (Y q Y j ) / (Y j+1 Y j ) (2) Substituting X_ratio value in formulas (3) and (4), fuel injection quantity Z (p, j), Z (p, j+1) corresponding to Y j, Y j+1 can be obtained from neighbor 4 lattice points of X p, Y q, i.e., Z (i, j), Z (i+1, j), Z (i, j+1) and Z (i+1, j+1). Z (p, j) = (Z (i+1, j) Z (i, j) ) * X_raio + Z (i, j) (3) Z (p, j+1) = (Z (i+1, j+1) Z (i, j+1) ) * X_raio + Z (i, j+1) (4) Furthermore, applying these values to formula (5), reference fuel injection quantity Z (p, q) can be approximated. Z (p, q) = (Z (p, j+1) Z (p, j) ) * Y_ratio + Z (p, j) (5) For purpose to easily identify indices following vehicle condition, some functions are equipped on PC application software. For example, radar chart indicates closed-up lattice points and surroundings to parameters received. Simultaneously, cell cursor in which represents lattice points approaching to current vehicle condition can move and track automatically. TARGET FUEL INJECTION QUANTITY DECISION Referring to λ sensor value, target fuel injection quantity Z (p, q) is decided by increasing or decreasing current fuel injection quantity. For purpose to easily observe λ sensor value during fuel adjustment, function for monitoring current control parameters on screen window is equipped on PC application software. ADJUSTMENT PROPORTION CALCULATION Z_ratio, proportion of target fuel injection quantity Z (p, q) and reference fuel injection quantity Z (p, q), is calculated by formula (6). Z_ratio = Z (p, q) / Z (p, q) (6) ADJUSTMENT PROPORTION REFLECTION Consequently, fuel adjustment value for neighbor 4 lattice points of X p, Y q, i.e., Z (i, j), Z (i, j+1), Z (i+1, j), and Z (i+1, j+1), is obtained from proportional multiplication by original value, as shown in formulas (7)~ (10). Z (i, j) = Z (i, j) * Z_ratio (7) Z (i, j+1) = Z (i, j+1) * Z_ratio (8) Z (i+1, j) = Z (i+1, j) * Z_ratio (9) Z (i+1, j+1) = Z (i+1, j+1) * Z_ratio (10) Proportion of target fuel injection quantity and reference fuel injection quantity, i.e., Z_ratio, is sent to ECU. ECU receives this value and calculates fuel injection quantity of 4 lattice points according to formulas (7)~(10) to approximate theoretical air fuel ratio. In the meanwhile, PC application software implements same calculation, and stores results in PC, replacing original values of corresponding 4 lattice points formerly used for reference fuel injection quantity calculation. For purpose to easily distinguish calibrated area from others, function that background color of calibrated area changes automatically on screen window is equipped on PC application software. COMPLETED FUEL INJECTION MAP DATA REFLECTION At the moment REFERENCE FUEL INJECTION QUANTITY CALCULATION to ADJUSTMENT VALUE REFLECTION for all adjustment area have been finished, a completed fuel injection map is -30-

built-up in PC. Writing this data into ROM of ECU realize completed fuel injection reflection, and thus accomplish fuel adjustment which is fundamental in vehicle calibration.

5 built-up in PC. Writing this data into ROM of ECU realize completed fuel injection reflection, and thus accomplish fuel adjustment which is fundamental in vehicle calibration. Sequential procedure for fuel injection map adjustment is summarized in Fig. 5. In case that number of cylinders is two or more, reference fuel injection quantity is calculated for a target cylinder which is selected for deriving adjustment proportion, and adjustment proportion is reflected to fuel injection quantity of this cylinder. Target cylinder shift makes it possible to adjust fuel injection map of other cylinder(s). Whole control logic that becomes adjustment target is introduced into PC application software in advance, ECU software and PC application software are structured available to shift adjustment target of control logic dynamically. Additional RAM area in ECU is not necessary because same RAM area is constructed to deal with the transformation for Procedure Reference fuel injection quantity calculation PC application software Adjustment A 4-point interpolation calculation Current fuel value Z(p, q) ECU software Parameter of vehicle condition adjustment target shift. Calibrated data for each control is wholly stored in PC, and adjustment target shift does not cause damage to final adjustment result. After all calibration completed, it is practicable to write ROM of ECU. For purpose to real-timely shift according to adjustment target of control logic in multi-cylinder motorcycle calibration, function that is selectable from catalog on screen window is equipped on PC application software. Fig. 6 illustrates screen widows of PC application software used in actual fuel adjustment as an example, including radar window, monitoring window, mapping window and window. Radar window shows positional relation of vehicle condition parameters to neighbor lattice points and surroundings. Monitoring window indicates current vehicle control parameters including λ sensor value. Mapping window is provided for adjustment target shift, volume increase or decrease to approach target adjustment value. Map data window is linked with radar window expressing value of lattice points for adjustment, and the color of calibrated area is changed automatically. Monitoring Window Map data Window Target fuel injection quantity decision Adjustment proportion calculation Increasing or decreasing fuel value according to λ sensor into. Target fuel value Z (p, q) Calculating proportion of Z (p, q) / Z(p, q) Z_ratio Adjustment proportion reflection Reflecting proportion Z_ratio to values of 4 lattice points Z (i, j), Z (i, j+1) Z (i+1, j), Z (i+1, j+1) Store 4 values in map data Reflecting proportion Z_ratio to values of 4 lattice points Z (i, j), Z (i, j+1) Z (i+1, j), Z (i+1, j+1) Fig. 6 Radar Window Mapping Window Screen window of PC application software for fuel adjustment Completed fuel injection reflection Fig. 5 A No All calibration Completed? Yes ECU ROM Write ROM data Fuel injection map adjustment procedure SUBSTANTIATION A variety of data adjustment for control logic exists in vehicle calibration. Besides fuel injection map adjustment, calibration to other adjustment -31-

6 Vehicle Calibration Techniques Established and Substantiated for Motorcycles target of control logic is accomplished by same adjustment procedure just replacing contents of, control logic equipped in PC application software for obtaining same result as ECU, parameters received From these confirmation results, effectiveness and validation of proposed vehicle calibration techniques for motorcycles based on mass-production ECU have been proved. from ECU, and adjustment proportion sent to ECU, demonstrating that proposed calibration techniques are effective for different kinds of control logic. As stated in COMPLETED FUEL INJECTION MAP DATA REFLECTION, number of cylinders from two to more is applicable so that proposed calibration techniques are effective for various engine models of vehicle. ADJUSTMENT VALUE REFLECTION mentioned that PC sends only variation (proportion of target value to reference value) to ECU during calibration regardless of control classification. Adjustment accuracy, number of cylinders and application coverage is satisfied using minimum RAM capacity in ECU as a result. Functions equipped on PC application software can improve operability and visibility for tester, leading to reduce human error in vehicle calibration. Proposed techniques have been practiced on various kinds of mass-production ECU using CPU specified in Table 1 [for example, 7] and constructed PC application software. Such ECU/PC-application combination has been implemented even in fuel injection map adjustment for motorcycles with single-cylinder engine, in which the capacity of mass-production ECU is most reduced. In this case, only proportion of target value to reference value is regarded as necessary adjustment value, and just 1 byte ensured in RAM area of ECU makes possible for vehicle calibration. SUMMARY/CONCLUSIONS Several controls to be calibrated simultaneously have been once raised as an idea. For human being, it is not realistic for a tester to perform adjustment on various control logic in vehicle calibration at the same time. Thus, adjustment target of control shift is proposed as solution from experiments. Applying this concept, target/type of vehicle calibration is subdivided or simplified, and using minimum RAM capacity in ECU becomes possible. Consequently, architecture introducing ECU produced for massproduction into vehicle calibration has been constructed. Proposed techniques have been applying to Keihin s motorcycle ECU development entirely, and usefulness of the techniques has been proven through mass-production development practice. The most distinctive characteristic of proposed techniques is that, logic for obtaining same calibration values is equipped on both sides of PC application software and ECU software. For same control target, calculation result from PC application software is equal to that from ECU software if same parameter which indicates vehicle condition is used. In case that control value is adjusted on PC application software s side, variation from reference value is calculated and sent to ECU, and then, control value on ECU side is modified as reflection of variation. Validity of variation value is probably confirmed in order to prevent unintended data reflection, e.g., Table 1 CPU specification for mass-production ECU Processor Type bits Frequency M Hz Capacity of RAM 4 32 k Bytes Capacity of ROM k Bytes data corruption caused by communication error. A typical vehicle calibration technique which edits control data in RAM directly might cause damage to vehicle, if using an unintended control data caused by communication error or human error. Proposed -32-

techniques have superiority at this point of view.

state, which is expected to be improved in the near future. REFERENCES 1. Kiyohara, K., Asou, R., Yuuki, T.

, Nakano, Y., Development of carburetors and element parts of fuel injection system for motorcycles, SETC Technical Paper JSAE 20056598/SAE 2005-32- 0068 3. Nakano, Y., Araki, K., Akiyama, H.

7 techniques have superiority at this point of view. However, comparing with the calibration technique that edits RAM data directly, proposed techniques have inferiority because delay for control data reflection restricts vehicle calibration to steady state, which is expected to be improved in the near future. REFERENCES 1. Kiyohara, K., Asou, R., Yuuki, T., Development of Low-cost Fuel Injection Control Unit for Small Motorcycles with Single-cylinder Engine, SETC Technical Paper JSAE /SAE Akiyama, H., Suzuki, K., Araki, K., Nakano, Y., Development of carburetors and element parts of fuel injection system for motorcycles, SETC Technical Paper JSAE /SAE Nakano, Y., Araki, K., Akiyama, H., Ouchi, K., Akamatsu, S.,, Development of the Electronic Fuel Injection Control Unit of Small Motercycle, International Journal of Automotive Engineering. 36(5) 22-28, 2005 (in Japanese) 4. Robert Bosch GmbH, Automotive Handbook Automotive Handbook (Japanese, 3rd Edition), Nikkei Business Publications, ISBN , Tsunokawa, K., Suda, T., Kanno, S., Massproduction ECU based vehicle calibration techniques, Japan Patent, February 6, 2012 (Registered). 6. Kanno, S., Engine calibration systems and engine calibration methods, Japan Patent / / , April 15, 2010 (Request for Substantive Examination). 7. Keihin Corporation, Motorcycle and General- Purpose Products Large and Small Motorcycle Products, http// product/bike.html, April Authers ABBREVIATIONS ECU Electronic Control Unit RAM Random-Access Memory CPU Central Processing Unit PC Personal Computer ROM Read-Only Memory Satoru KANNO Koichi TSUNOKAWA Takashi SUDA It is an actual proof that our tools, which apply proposed new techniques to motorcycles considering calibration environment, contributes for the benefit of both OEM (completed vehicle manufacturer) and supplier (Keihin). Tool development will continue to match a background of advancing diversification of needs in the future. (KANNO) I have been working on research and development of algorithms and tools for vehicle Measurement, Calibration, and Diagnostics (MCD) more than 20 years. This paper introduced one of achievements obtained by my colleagues and me, that is, consistent vehicle calibration techniques for ECU of motorcycles with single- or multi- cylinder engine, in which the capacity of CPU is restricted. Facing to daily progress of vehicle control, adaptable MCD technology exploration and its practical application will be continued henceforth. (TSUNOKAWA) Applying customized supportive tools is important for Development Process Improvement and Regular Process Quality Stabilization. Developing and supplying customized supportive tools continuously will make OEM s vehicles development more profitable. (SUDA) -33-

Cloud Connector 徹底解説. 多様な基盤への展開を可能にするための Citrix Cloud のキーコンポーネント A-5 セールスエンジニアリング本部パートナー SE 部リードシステムズエンジニア. 哲司 (Satoshi Komiyama) Citrix

Cloud Connector 徹底解説. 多様な基盤への展開を可能にするための Citrix Cloud のキーコンポーネント A-5 セールスエンジニアリング本部パートナー SE 部リードシステムズエンジニア. 哲司 (Satoshi Komiyama) Citrix 1 2017 Citrix Cloud Connector 徹底解説多様な基盤への展開を可能にするための Citrix Cloud のキーコンポーネント A-5 セールスエンジニアリング本部パートナー SE 部リードシステムズエンジニア小宮山哲司 (Satoshi Komiyama) 2 2017 Citrix このセッションのもくじ Cloud Connector 徹底解説 Cloud Connector