Hitachi Astemo (Japan)

Frequency-modulated continuous wave radar techniques typically have inadequate angular resolutions due to the limited aperture sizes of antenna arrays in spite of employing multiple-input multiple-output (MIMO) techniques. Therefore, despite the existence of multiple objects, angularly close objects with similar distances and relative velocities are recognized as one single object. Autonomous driving requires the accurate recognition of road conditions. This requirement is one of the critical issues to be solved to distinguish significantly close objects. This paper proposes a technique referred to as an antenna element space pseudo-peak suppressing (APPS) method to resolve angularly close targets. The proposed APPS method aims to identify closely spaced objects on roads. These angularly close targets cause a single peak in a spatial spectrum obtained by a beamformer-based angle estimation. The APPS considers this single peak as pseudo. The APPS radar cancels this pseudo peak from the spatial spectrum. Then, the obtained residual received signal is analyzed. With these procedures, the APPS identifies the number of targets. The APPS also estimates the target angles. The proposed APPS is experimentally validated using a typical single-chip MIMO-based radar evaluation board with three transmit (TX) and four receive (RX) antennas. The experimental results confirm that the proposed APPS successfully resolves angularly close pseudo targets with an angle difference of approximately [Formula: see text].

Permanent magnet synchronous motors (PMSMs) are utilized in a wide range of applications as high-power-density and highly efficient drive sources. However, a PMSM generates electromagnetic vibration and loss caused by space and time harmonics. In this article, we propose a synchronous pulsewidth modulation control method for shifting the carrier wave phase against the modulation wave phase. As the proposed control matches the vibration frequencies caused by space and time harmonics, the pulsation caused by the space harmonics is canceled out by the pulsation caused by the time harmonics with the phase shift of the carrier wave. Experiments on the proposed control demonstrate that vibration at a specific frequency was reduced by 46% at 7900 rev/min. In addition, to change the carrier phase with small <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis current harmonics, magnet eddy-current loss was reduced by shifting the carrier wave phase. The temperature of a magnet was measured in a heat-run test, and the temperature rise of the magnet could be suppressed by 5 K.

This paper focuses on estimating the angle and size of different-sized targets using a radar system that estimates the angles of trucks, vehicles, bicycles, and pedestrians. The problem is that the presence of a sidelobe from the larger target degrades the accuracy of estimating the angle and size of the smaller target in multiple target detection. In this paper, a novel scheme, called antenna element space interference cancelling (AIC), is proposed for reducing the influence of the sidelobe. The performance of the proposed AIC radar system was evaluated through both computer simulations and experiments. The simulation results show that the proposed AIC radar system can estimate the angles of smaller targets within a 1-degree error, and the size estimation error is 1 dB. The experimental results also show that the proposed AIC radar is effective in detecting smaller targets that cannot be detected with traditional methods due to the sidelobes of larger targets.

&lt;div&gt;To reduce CO&lt;sub&gt;2&lt;/sub&gt; and pollutant emissions from internal combustion engines worldwide, both electrification and efficiency improvement of internal combustion engines are necessary. Pre-chamber (PC) combustion is one of the promising technologies for realizing the above objectives. This article investigates the ignition specification for the PC system with the swirled orifice layout to extend the stability limit of the lean burn. The computational fluid dynamics (CFD) simulation results showed that the discharge channel would be exposed to the direction-fluctuating velocity, where the discharge channel moves around on the electrode surface of the spark plug (SP) and stays at the electrode gap area without channel stretching. To keep a stable discharge channel against the flow in the PC and promote the initial flame propagation in a short time, the high current coil with a short discharge duration was proposed. For the concept validation, a single-cylinder engine test was conducted with four ignition coils with different specifications. The ignition coil with a high current and short discharge duration showed the equivalent effect of the lean limit expansion to the high secondary energy coil. Meanwhile, the ignition coil with a lower current showed the worst lean limit, and signal oscillations in the secondary current were observed, which indicated the disturbance of the spark channel. Furthermore, to estimate the effective energy ratio of the secondary energy which has contributed to the flame propagation, the secondary energy generated before the mass fraction burn of 2% (MFB02) was calculated as the effective secondary energy, and the rest of the energy was regarded as marginal secondary energy. It is expected that the marginal secondary energy has a correlation with the combustion stability, provided that enough amount of the secondary current was given. Controlling the marginal energy amount depending on the combustion state will be the key to efficient energy use while maximizing the combustion performance. Based on the investigations, the secondary current was the essential parameter contributing to the discharge channel stability. The ignition coil with the high current was identified as the preferred ignition specification for the PC.&lt;/div&gt;

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Future emission regulations require further development for internal combustion engines operating on gasoline. To comply with such regulations and simultaneously improve fuel efficiency, major development trends are found in reduced displacements, increased compression ratios and turbocharging. To counteract such engines’ increased tendencies to knocking combustion, direct fuel injection systems are necessarily applied. Compared to standard port fuel injection, direct injection systems cause increased particle emissions.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;State-of-the-art magnet-driven gasoline direct injectors are capable of realizing various injection events of small injected mass per event and short dwell time between one another. Thereby, they facilitate multiple injection strategies, able to overcome the drawbacks of direct injection systems in relation to exhaust emissions. However, the full potential of multiple injection strategies is not yet taken advantage of. An algorithm-based approach was developed to automatically design multiple injection patterns following thermodynamical and geometrical considerations to make use of the possible advantages. In this manner, impingement of neither piston nor liner is ensured, suppressing one dominant mechanism for particle formation and incomplete combustion. Furthermore, adaptions to different operation strategies can be taken into account for the calculations.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;This study describes the development and features of the before-mentioned algorithm and the different steps undertaken to calibrate it to a distinct gasoline direct injector. This study focuses on the methodology of calibration. A sequence of preliminary measurements was executed, including measurements in a spray chamber and an injection rate analyser. The calculated injection patterns have subsequently been used to operate a single-cylinder research engine. With those measurements, the feasibility of the approach was demonstrated. To present engine-operation related advantages of the approach, the section of results contains different view angles on combustion and emission behaviour.&lt;/div&gt;&lt;/div&gt;

The purpose of this study is to develop model predictive control (MPC), which addresses MIMO system optimization control problem under constrains while providing efficient engine calibration process, and to be applied to an intake system control in a turbocharged spark ignition engine. Extended Kalman filter, which was based on an air flow sensor and a pressure sensor, was employed to achieve robustness against actual variations and MPC plant model reduction. The control methodology was demonstrated in MILS through its application to torque and EGR cooperative control using throttle and EGR valves. The results show the control outputs are in good agreement with reference trajectories under various transient operations without large amount of calibration efforts associated with the target valve position.

In gasoline engines with a higher compression ratio, abnormal combustion, such as pre-ignition and knocking, tends to occur due to higher temperature in the combustion chamber, which leads to lower engine performance. To prevent pre-ignition from occurring, we propose a pre-ignition-prevention control method that involves using an ion-current sensor integrated in an ignition system. The pre-ignition and precursory cycles are detected from the ion-current intensity and spark-discharge duration estimated from ion-current signals. Fuel-injection is increased to cool the mixture in the combustion chamber after the abnormal combustion (precursory) cycle is detected. In a commercial gasoline engine, it was demonstrated that our method can prevent pre-ignition combustion by setting a proper threshold for precursory-cycle detection. The effectiveness of the fuel-injection control was analyzed.

We propose an abnormal-state-discrimination method for the in-vehicle communication channel with a power-over-coax (PoC) circuit. The proposed method uses digital data, such as equalizer parameters and error information, that can be obtained from general serializer/deserializer large-scale integrated circuits. Therefore, no additional components are required to diagnose the abnormal state of the channel. We specifically focus on detecting an anomaly of a PoC filter.

This report presents a mechanical winding- changeover system to improve energy consumption of traction motors for automobiles. We have adopted multi contacts to downsize the winding-changeover device and established the operation principle which does not occur any contact arc, where the switching timing is controlled so that the motor internal voltage is constantly below the inverter DC voltage. A developed winding-changeover device is downsized by half compared with the conventional relay structure of 5L, with rated current of 440 Arms, and will ensure the longer lifetime of the switching contact. The actual test of 1.5 kW induction motor system demonstrated that the contact arc did not occur at the winding changeover operation during motor acceleration.

This paper presents a study to quantify the difference in roll feel experienced by the driver with a change in damper characteristics between “comfort” and “sport” mode. The vehicle and driver’s motion are measured during the double lane change maneuver. In “sport” mode, the timing of steering operation was found to be faster (P = 0.0456), which can be explained by the driver being able to make quick upper body corrections to resist the slow vehicle roll motion. This difference in steering operation because of the man-machine feedback system can be considered as an objective measure to quantify roll feel.

This paper proposes a power-supply-voltage adjustment method for low-noise signaling of in-vehicle highspeed communication systems involving cameras using a power over coax (PoC) circuit. We introduce a method of detecting the PoC filter degrading from the change in the equalizer parameters of serializer/deserializer (SerDes) LSIs and determine the appropriate set voltage value from their change points.

This paper proposes initial rotor position estimation technique in three-phase permanent magnet synchronous motors (PMSMs) based on the magnetic saturation and saliency. Proposal technique extracts phase current dynamics caused by magnetic saturation and saliency respectively and simultaneously. Furthermore, this method has robustness against rotor position dependencies of d- and q-axis inductance. Therefore, this technique estimates initial rotor position accurately and shortly.

The field of autonomous vehicle research is advancing rapidly, necessitating platforms that meet real-time performance, safety, and security requirements for practical deployment. AUTOSAR Adaptive Platform (AUTOSAR AP) is widely adopted in development to meet these criteria; however, licensing constraints and tool implementation challenges limit its use in research. Conversely, Robot Operating System 2 (ROS 2) is predominantly used in research within the autonomous driving domain, leading to a disparity between research and development platforms that hinders swift commercialization. This paper proposes a collaboration framework that enables AUTOSAR AP and ROS 2 to communicate with each other using a Data Distribution Service for Real-Time Systems (DDS). In contrast, AUTOSAR AP uses Scalable service-Oriented Middleware over IP (SOME/IP) for communication. The proposed framework bridges these protocol differences, ensuring seamless interaction between the two platforms. We validate the functionality and performance of our bridge converter through empirical analysis, demonstrating its efficiency in conversion time and ease of integration with ROS 2 tools. Furthermore, the availability of the proposed collaboration framework is improved by generating a configuration file automatically for the proposed bridge converter.

Permanent magnet synchronous motors (PMSMs) are utilized in a wide range of applications as high-power-density and highly efficient drive sources. However, a PMSM generates electromagnetic vibration and loss caused by space and time harmonics. In this paper, we propose a synchronous PWM control method for shifting the carrier wave phase against the modulation wave phase. As the proposed control matches the vibration frequencies caused by space and time harmonics, the pulsation caused by the space harmonics is canceled out by the pulsation caused by the time harmonics with the phase shift of the carrier wave. Experiments on the proposed control demonstrate that vibration in a specific frequency was reduced by 46% at 7,900 rev/min. In addition, to change the carrier phase with small current harmonics, magnet eddy-current loss was reduced by shifting the carrier wave phase. The temperature of a magnet was measured in a heat run test, and the temperature rise of the magnet could be suppressed by 5K.

This research aims to quantify driver ride comfort due to changes in damper characteristics between comfort mode and sport mode, considering the vehicle’s inertial behavior. The comfort of riding in an automobile has been evaluated in recent years on the basis of a subjective sensory evaluation given by the driver. However, reflecting driving sensations in design work to improve ride comfort is abstract in nature and difficult to express theoretically. Therefore, we evaluated the human body’s effects while driving scientifically by quantifying the driver’s behavior while operating the steering wheel and the behavior of the automobile while in motion using physical quantities. To this end, we collected driver and vehicle data using a motion capture system and vehicle CAN and IMU sensors. We also constructed a three-dimensional musculoskeletal mathematical model to simulate driver movements and calculate the power and amount of energy per unit of time used for driving the joints and muscles of the human body. Here, we used comfort mode and sport mode to compare damper characteristics in terms of hardness. In comfort mode, damper characteristics are soft and steering stability is mild, but vibration from the road is not easily transmitted to the driver making for a lighter load on the driver. In sport mode, on the other hand, damper characteristics are hard and steering stability is comparatively better. Still, vibration from the road is easily transmitted to the driver, which makes it easy for a load to be placed on the driver. As a result of this comparison, it was found that a load was most likely to be applied to the driver’s neck. This result in relation to the neck joint can therefore be treated as an objective measure for quantifying ride comfort.

Edge devices with strict safety and reliability requirements, such as autonomous driving cars, industrial robots, and drones, necessitate software verification on such devices before operation. The human cost and time required for this analysis constitute a barrier in the cycle of software development and updating. In particular, the final verification at the edge device should at least strictly confirm that the updated software is not degraded from the current it. Since the edge device does not have the correct data, it is necessary for a human to judge whether the difference between the updated software and the operating it is due to degradation or improvement. Therefore, this verification is very costly. This paper proposes a novel automated method for efficient verification on edge devices of an object detection AI, which has found practical use in various applications. In the proposed method, a target object existence detector (TOED) (a simple binary classifier) judges whether an object in the recognition target class exists in the region of a prediction difference between the AI’s operating and updated versions. Using the results of this TOED judgement and the predicted difference, an automated verification system for the updated AI was constructed. TOED was designed as a simple binary classifier with four convolutional layers, and the accuracy of object existence judgment was evaluated for the difference between the predictions of the YOLOv5 L and X models using the Cityscapes dataset. The results showed judgement with more than 98.6% accuracy and 1.6% over detection, thus indicating that a verification system adopting this method would be more efficient than simple analysis of the prediction differences.

For systems that are not observable at an equilibrium to be stabilized, output-feedback stabilization is considerably challenging. This paper solves this control problem for the case-study of a second-order system that is bilinear and affine, both in the input and the output, but it is unobservable at the target equilibrium. The case-study defines a class of non-uniformly observable systems and stems from automotive-control applications. Our main contribution is a novel observer-based hybrid controller that achieves asymptotic stabilization semiglobally. The controller relies on a switched observer that estimates the state, provided that the latter is ‘kept away’ from the singular equilibrium. To achieve both competing tasks, stabilization and estimation, the controller relies on the keen construction of a piecewise-constant, converging, output reference. Our main results are illustrated via numerical simulations on a meaningful example.

This paper proposes a direct-drive system of in-wheel motors and discusses its superiority compared with a conventional gear-drive system. The proposed technology enables the installation of high-power motor into the wheel and more expansive interior and battery installation spaces, thus moving the world one step closer to a zero-emissions society. The new motor transmits the high drive force directly to the wheels, and its lightweight design with 40 Nm/kg torque density significantly limits the weight increase traditionally associated with in-wheel units. We have theoretically quantified that the developed direct-drive system is 10-30<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">%</sup> lighter than the gear drive system. Moreover, the direct-drive system rotates much lower rotation than the gear drive, which allows for immersion oil cooling within the motor without the significant increase in fluid friction loss. Measurement of the prototype demonstrated the maximum output torque of 960 Nm at 600 min<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup>, and high cooling performance at 50 % load condition.

Real drive emissions (RDE) regulation were introduced from Euro6-d regulation. In order to achieve the regulation value of PM(Particulate Matter) emission in the RDE regulation, it is effective to install GPF(Gasoline Particulate Filter) system. To prevent GPF corruption , GPF system needs “PM emission amount estimation model” that estimates PM emission amount from direct injection gasoline engine to estimate PM corrected amount. Some models, for example packet model and map-based model, have been proposed as PM emission amount estimation model. However, these models have problems in terms of calculation load and accuracy for On-board calculation. Purpose of this research is to study On-board PM emission amount estimation model . We proposed a new model method of physical quantities that dominate PM production. Developed model uses probability density function of mixture fraction space so that mixture and fuel adhesion can be treated uniformly as a fuel distribution in cylinder. Also, variance of mixture-derived probability density function and fuel adhesion ratio are functionalized by a second-order polynomial of engine control parameters, and can be applied to multiple operating conditions. The developed model was verified by comparison with measurement data. Under 25 degC of coolant temperature(19 operation points), the estimated error was during 0% and 59% and average estimated error was 19%.

Automotive inverters are required to comply with high voltage conducted emission (HVCE) tests as regulated in the international electromagnetic compatibility (EMC) standard CISPR25. One of the HVCE tests is to evaluate the common mode (CM) current on the HV cables due to the switching transients. A filter is usually employed to suppress the CM current and for filter development, an effective simulation methodology is beneficial. However, how to model the noise sources in an accurate but time efficient way remains challenging, especially for ordinary EMC engineers. In this paper, a two terminal Norton equivalent circuit is derived to predict the CM current in an automotive inverter motor drive system based on a standard CISPR25 measurement. The prediction accuracy is validated experimentally to be < 5 dB up to 50 MHz and within 10 dB up to 108 MHz. The approach is chosen and applied due to its easy implementation and high accuracy, which makes it a promising tool in practical filter development for EMC engineers.