Kimitoshi Tsuji

Analysis of alternator regeneration using VHDL-AMS vehicle system simulation

Recently, multi domain simulation is becoming indispensable for discussing system performance of a vehicle. The system in the vehicle became more complex and larger in past ten years. And the system is required to catch up tough issues e.g. CO2 reduction. This paper shows the modeling method of power network system in a vehicle, regeneration of the alternator and the effect of reduction CO2.

Novel Power Conversion System for Cost Reduction in Vehicles with 42V/14V Power Supply

In recent years, attention is being given to 42V power supply technology for solving the problem of increased power demand in vehicles. Since 2001, Toyota Motor Corporation has been marketing a mild hybrid system (THS-M) in order to further improve fuel economy and reduce emissions; this system requires both 42V and 14V power sources. The THS-M system consists of a 42V motor generator (M/G) connected to the engine crankshaft with a belt; an inverter; a 36V battery; a DC/DC converter for stepping down the 42V power supply to a conventional 12V battery; and high-power related electrical components. These components require additional costs, which must be reduced in order to increase the sales volume of THS-M vehicles. We have devised a method to eliminate the conventional DC/DC converter from the THS-M, and as a result we have developed a new, revolutionary power conversion system (multi-function inverter). Instead of using a DC/DC converter, we derived a 14V power line from the neutral point of the motor generator, and added a reactor (a type of smoothing inductor) in this line for reducing ripple. In addition, we applied a new inverter switching system which allows us to simultaneously and independently control both the 14V and 42V system voltages, which are taken from the motor-generator drive, and connected to the 12V and 36V batteries, respectively. The paper reports on the principle of operation and the test results, including torque and efficiency characteristics of the multi-function inverter.

EPS System Analysis using Multi Domain Simulation for Power Network Design in a Vehicle

An EPS system requires large electrical power depending on steering torque. Recently, the required steering torque is getting larger especially for luxury sedans and large Sports Utility Vehicles. In heavy vehicles, the steering without driving and the emergency steering are becoming a very heavy load for a conventional 12 V battery system. Therefore, it is important to estimate the battery power management and the voltage behavior using the multi domain simulation for concept planning. The purpose of this research is to show that multi domain simulation is effective to discuss power electronics system and power network in the vehicle. This paper describes modeling method for an EPS system using VHDL-AMS. Static steering and dynamic steering results were validated in comparison with experimental data.

An energy analysis for alternator regeneration system using VHDL-AMS multi domain simulation

Recently, the use of multi domain simulation is becoming indispensable for discussing system performance of a vehicle. In this paper, the simulation technology applied to CO2 reduction using regeneration for a conventional 12V battery system vehicle is discussed. The energy analysis results for Drive Shaft, Brake and Alternator regeneration shows the optimized Alternator performance for the fuel economy.

A study of vehicle energy analysis during warming up process using VHDL-AMS multidomain simulation

In this paper, by employing thermal characteristic modeling to the main components of the vehicle model for example, engine, transmission and battery, we examine the heat energy management and fuel consumption of the testing drive patterns especially during warming up process. The simulation data agree well with measurement data. Our vehicle simulation results provide VHDL-AMS validity for multi-domain energy management and the vehicle system planning.

The automotive system simulation by using multi domain modeling technique

The goal of this research is how to realize automotive system simulation by using multi domain simulation technologies. This paper illustrates how to utilize the multi domain simulation model for creating and validating the automotive system simulation. This technique is verified by simulations and experiments.

EPS system analysis using multi domain simulation for conventional 12V power network design in a vehicle

An EPS system requires large electrical power depending on steering torque. Recently, the required steering torque is getting larger especially for luxury sedans and large Sports Utility Vehicles. In heavy vehicles, the steering without driving and the emergency steering are becoming a very heavy load for a conventional 12V battery system. Therefore, it is important to estimate the battery power management and the voltage behavior using the multi domain simulation for concept planning. The purpose of this research is to show that multi domain simulation is effective to discuss power electronics system and power network in the vehicle. This paper describes modeling method for an EPS system using VHDL-AMS [1] [2]. Static steering and dynamic steering results were validated in comparison with experimental data

The power performance and fuel economy estimation for vehicle concept planning and design using VHDL-AMS HV full vehicle simulation

In order to reduce CO2, in many cases, CO2 performance conflicts with power performance and comfort. We have to compromise between these requirements and produce a good solution. In early stages of vehicle development, the decisions for large-scale systems are important. Using a whole system simulation is effective for making these decisions. In this paper, we propose VHDL-AMS multi-domain simulation technique for the estimation of the vehicle performance at the concept planning stage. The VHDL-AMS is IEEE and IEC standardized language, which supports not only multi domain (physics) but also encryption. The common modeling language and encryption standard is indispensable for full vehicle simulation. By the HV Full Vehicle model, the fuel economy, the effect of heat energy recovery from the exhaust gas, and the power performance are discussed. The fuel economy was estimated using LA#4 driving pattern and the base simulation model validation result was that simulation was 22.0km/L and measurement was 21.7km/L (error 1.4%). The energy management using an exhaust gas heat exchange system realized 10.3% fuel consumption improvement during warming up. As for the power performance, the simulated acceleration time of 0-100km/h was 11.12sec and the measured vehicle time was 11.27sec. The error between simulation and actual measurement result was 1.4%. We showed that the application of VHDL-AMS multi-domain HV simulation is effective for the vehicle concept planning. Since the HV model uses embedded real control software, the VHDL-AMS modeling can be used as SIL at system control development stage.

Requirements to Models of Automotive System Development for Future Model-Based Design

Abstract Optimum designs by simulation and their model distributions can activate and improve production and development processes of automotive industries by cooperative development among different organizations. Simulation models are investigated for standardizations and distributions in a working group named “investigating committee on model development and distribution by international standard description” in JSAE. Present subjects and future requirements to models of automotive simulation for model-based design (MBD) are discussed.

VHDL-AMS Full Hybrid Vehicle Simulation Model for the Concept Planning and the Power Performance and Fuel Economy Estimation results

Abstract By VHDL-AMS (IEC61691-6, IEEE1076.1) Full vehicle simulation, the fuel economy, the effect of heat energy recovery from the exhaust gas, and the power performance were discussed. The basic model performance was validated by PRIUS. The fuel economy for the LA#4 driving pattern was 22.0km/L by the simulation and on other hand measurement was 21.7km/L (error 1.4%). The energy management using an exhaust gas heat exchange system realized 10.3% fuel consumption improvement during warming up. As for the power performance, the simulated acceleration time of 0-100km/h was 11.12sec and the measured vehicle time was 11.27sec. The error between simulation and actual measurement result was 1.4%. We showed that the multi-domain full vehicle simulation is effective for the vehicle concept planning. Since the HV model uses embedded real control software, the VHDL-AMS modeling can be used as SIL at system control development stage.