Application Note. Using PZAmp with dspace MicroAutoBox and RapidPro. Version 1.3

Transcription

1 Application Note Using PZAmp with dspace MicroAutoBox and RapidPro Version 1.3

2 Document Information: Revision: 1.3 Status: final Date of creation: Date of print: VEMAC GmbH & Co. KG Krantzstr. 7, Halle 33A Aachen, Germany Tel.: +49 (0) 241 / Fax: +49 (0) 241 / contact@vemac.de Copyright VEMAC GmbH & Co. KG, Aachen

3 Change History Version Date Status Author Changes Draft RE Document created Draft HROSS Section added Draft DB RapidPro info added Final RE Pictures actualized, final approval 3

4 Content About this solution Introduction Variants Recharging amplifier variant Fast switching amplifier variant Calibration and Flash Functional Description MicroAutoBox / modular RCP System and RapidPro Configuration PZAmp Configuration Connection diagram How to use Example application Contacts

5 About this solution PZAmp is designed to drive up to six Piezo injectors either for diesel but also for gasoline common rail applications. Figure 0.1: PZAmp Piezo-Amplifier The injection impulses are generated by a dspace RapidPro System in combination with MicroAutoBox or dspace modular RCP System in accordance to the crank angle. 5

6 1 Introduction PZAmp was designed to drive up to six piezo-injectors. On the input side a dspace MicroAutoBox/RapidPro combination is connected, to trigger PZAmp. On the output side the injectors are directly connected. PZAmp features two independent power stages (A & B), which drive up to three injectors each. Injection events are allowed to occur simultaneously on two injectors, which are connected to different power stages. Injectors, which are connected to the same power stage, have to be energized consecutively. PZAmp is a universal power stage to drive piezo injectors with a definable set of parameters. VEMAC offers a recommended set of parameters for each type of injector. For further and actual information please check or contact VEMAC. 1.1 Variants PZAmp is available in two different variants. While the recharging amplifier charges and discharges the piezo with a sinusoidal shape curve, the fast switching amplifier charges and discharges the piezo with small portions of electrical charge very fast one after another. The variant should be chosen depending on the used injection system. The following table gives an overview Table 1.1 Recommended PZAmp variants Recharging amplifier variant With this type of amplifier the piezo is loaded with a sinusoidal shape. By setting the internal DC/DC-voltage to different values, the effective voltage on the piezo is varied. The DC/DC-voltage might be adjusted according to the rail pressure, the ambient temperature or other conditions. 6

7 Figure 3-1 shows the piezo current and the piezo voltage parameterized at different settings of the DC/DC-voltage. The load time depends on capacity of the connected injector. It decreases with a smaller capacity and increases with a higher capacity. A typical value for the charge and discharge time is about 200µs (measured at a Continental piezo diesel injector). With this variant a partial load of the piezo is not possible Fast switching amplifier variant With this type of amplifier the piezo is loaded by small portions of electrical charge very fast one after another. By setting the internal DC/DC-voltage to different values, the effective voltage on the piezo and the effective rise gradient of the piezo voltage is varied. A higher DC/DC voltage causes a higher piezo voltage and also a faster rise gradient of the piezo voltage. 7

8 Voltage [V] Current [A] Application Note PZAmp 1.3 Figure 3-2: Partial Load Function with fixed and inceasing DC/DC voltage By using additional load inputs the injector charging can be stopped before the configured charge time has been is reached. Figure 3-2 shows the piezo voltage in accordance to the injection and load pulses on the amplifiers inputs. Figure 3-3 shows the piezo voltage measured at a BOSCH Gasoline piezo injector in accordance to different partial load pulse times no partial load 150µs partial load 100µs partial load ,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 Time [ms] Figure 3-3: Partial Load Function with fixed DC/DC voltage 8

9 1.2 Calibration and Flash The PZAmp parameters can be calibrated via a XCP over CAN connection. For this the dspace XCP-Toolkit is used. The appropriate A2L has to be loaded to the XCP Toolkit and after that the PZAmp parameters like the DC/DC Voltage are available in Simulink. For using PZAmp with another injection system than originally provided for, the system has to be re-flashed. This can be done at VEMAC. Alternatively an optional Flash-Tool-Kit is provided, that can be used by the customer to re-flash the system by himself. 9

10 2 Functional Description For building up an engine control system as full bypass MicroAutoBox is used to calculate the engine control model. An additional RapidPro system is used to generate digital pulses for injection and load synchronous according to the crankshaft. Triggered by these digital pulses PZAmp generates the power signals for the connected Piezo injectors. To parametrize PZAmp online it is connected via a CAN bus with the MicroAutoBox. Using the dspace XCP-on-CAN Bypass Blockset Tool-Kit parameters of PZAmp can be read or written, while the system is running. Figure 2.1 General setup of MicroAutoBox, RapidPro and PZAmp 2.1 MicroAutoBox / modular RCP System and RapidPro Configuration General information - The PZAmp input signal named Sync is for future purpose. Currently there is no function behind. - The PZAmp input signals Load 1 6 are optional. If the Partial Load Function is not used, then this input signals have to be connected to system ground. - To parameterize PZAmp by XCP-on-CAN during runtime is optional. PZAmp can be also used without CAN connection. Software - Standard dspace CDP (control development package) required. - ConfigurationDesk Configuration Version required - RapidPro Control Unit Blockset (RTI RPCU) required. - RTI CAN Blockset is optional, refer to chapter General information. - RTI Bypass Blockset is optional, refer to chapter General information. 10

11 Hardware - dspace MicroAutoBox or DS1005-based modular RCP System - RapidPro Control Unit - RapidPro module SC-CCDI 6/1 (DS1637) or SC-DI 8/1 (DS1642) for reading crankshaft and camshaft required. - RapidPro module SC-DO 8/1 (DS1646) or SC-DO 8/2 (DS1647) required Only open collector resp. low-side driver function has to be used. No pull-up resistor on module allowed! - RapidPro custom routing required. - In case PZAmp s Partial Load Function is used, then for each injection signal an additional load signal has to be controlled. Means for each injection two signals are required. (two channels on RapidPro hardware) Getting started / Hints The signal polarity of all channels on RapidPro digital output modules which are used to drive the injection and load signals have to be inverted by ConfigurationDesk. When using module type SC-DO 8/2 (DS1647) the Output driver mode for each channel has to be set to low side using ConfigurationDesk. Each RapidPro module requires an external ground connection. As a starting point for your Simulink model the Demo model from RTI RPCU for Engine Control can be used. When using RTI Bypass Blockset to parameterize PZAmp by XCP-on-CAN during runtime an a2l file is required. The corresponding a2l file can be obtained by VEMAC or dspace. When using the optional analog monitor output signals from PZAmp then four AD channels on MicroAutoBox or DS2004 have to be used. Recommended is a sample frequency of about 1MHz. 2.2 PZAmp Configuration PZAmp has to be flashed with the appropriate configuration for the connected injection system. Please use the PZAmp Flash Tool-Kit, if PZAmp has to be reflashed. 2.3 Connection diagram Figure 2.2 shows an example connection between MicroAutobox, RapidPro and PZAmp. 11

12 Figure 2.2 Example connection diagram of MicroAutoBox, RapidPro and PZAmp Note that simultaneous injections on two injectors are only possible, when they are connected to different power stages! Connect the output channels of one power stage only to injectors that are not activated simultaneously! 12

13 Signal Type Description VCC Power Power supply 10-15V GND Power GND, is also connected to PZAmp case Inj. 1-6 TTL, Injection pulses, open collector Injector opens with falling edge and closes with rising edge of the pulse Load 1-6 on RapidPro TTL, open collector on RapidPro Load pulses, Piezo loading is started with falling edge of injection pulse, if corresponding Load input is low, piezo load is stopped with the rising edge of the load pulse. For future purposes Sync TTL, open collector on RapidPro I out, U out Analog, 0..5V Injector current and voltage monitor output for each power stage HV+ High-voltage, High voltage power output for each power stage, positive terminal of power output injector Inj. 1-6 out High-voltage, power output Attention: High-Voltages of up to over 200V!! High voltage power output for each power stage, negative terminal of injector Attention: High-Voltages of up to over 200V!! 3 How to use Example application Picture 3.1: Example Simulink model for dspace MicroAutoBox II controlling PZAMP piezo power stage The modeling side of engine control with dspace MicroAutoBox and RapidPro is also highly modular. It is based on providing crank angle synchronous pulses which are used to trigger the ignition and injection power stages. To setup the angle synchronous pulse generation, crankshaft and camshaft sensor signals need to be captured. 13

14 Angle synchronous pulses are even used to trigger the A/D converter of the MicroAutoBox. Nearly every RapidPro System is different from each other due to the high modularity and flexibility of RapidPro. Therefore the example model has to be adapted to your RapidPro System in case the example model is reused for your application. Especially the I/O assignment in the RPCU blocks has to be checked. 14

15 Setup In the Setup subsystem are several blocks for configuring main or basic settings. The Setup subsystem (see picture below) provides access to - The RPCU setup block, to make your specific RapidPro System configuration available for the blockset by hwt file - the RPCU TPU timer setup block, for assigning TPU timer to engine control functionality - the crank/camshaft setup block, to define the used crank / cam pattern - the RTI Bypass setup block for controlling the PZAmp piezo power stage via CAN interface. Picture 3.2: The setup subsystem provides blocks for configuring the crank/cam pattern, timer control and for the CAN interface between MicroAutoBox II and PZAmp. Pulse pattern update timing The subsystem INT_Angles (see Picture 3.2) provides access to the pulse pattern update timing. Here are the interrupts defined which call the injection and load pulse generation. The interrupt angles have to be chosen in a way that the interrupt occur some crank angle degree before the pulse starts. 15

16 Injection pulse generation Picture 3.3: Cascaded model structure for injection pulse generation: A hardware interrupt (top right picture) calls the injection subsystem with the appropriate RapidPro pulse generation blocks. Generated injection pulses are directly coupled to the PZAmp power stage. The Sync pulse feature is not yet supported. Please delete the appropriate blocks. 16

17 Analog Input Picture 3.4: Definition of trigger pulse generation to start the A/D converter angle synchronous. An angle synchronous pulse is generated by RPCU_AABP_TPU block (Angle-Angle- Based-Pulse). The output pin of the pulse has to be wired externally to the A/D trigger input pin of the MicroAutoBox. 17

18 Picture 3.5: Triggered data transfer from A/D converter The A/D conversion starts by the external angle synchronous pulse (see picture 3.4 and Burst trigger settings in block mask). After A/D conversion start an internal timer samples the signal with 1MHz (see Conversion trigger settings in block mask). The conversion results are stored in a buffer with size If the buffer is full automatically an interrupt is generated which triggers the data transfer from ADC to the application. Output of the block ADC_Type4 is a vector with 8000 elements. 18

19 4 Contacts For any questions regarding PZAmp and injector connection please contact: VEMAC GmbH & Co. KG Krantzstr Aachen Germany Service Hotline: Phone: +49 (0) pzamp@vemac.de For any questions regarding Example and dspace configuration please contact: dspace GmbH Rathenaustrasse Paderborn Germany Service Hotline: Phone: +49 (0) support@dspace.de 19