Toyota

About: Toyota is a company organization based out in Safenwil, Switzerland. It is known for research contribution in the topics: Internal combustion engine & Battery (electricity). The organization has 40032 authors who have published 55003 publications receiving 735317 citations. The organization is also known as: Toyota Motor Corporation & Toyota Jidosha KK.

Robust and reduced-order filtering: new LMI-based characterizations and methods

Abstract: This paper addresses several challenging problems of robust filtering. We derive new linear matrix inequality (LMI) characterizations of minimum variance or H/sub 2/ performance and demonstrate that they allow the use of parameter-dependent Lyapunov functions while preserving tractability of the problem. The resulting conditions are less conservative than earlier techniques, which are restricted to fixed (not parameter-dependent) Lyapunov functions. The remainder of the paper discusses reduced-order filter problems. New LMI-based nonconvex optimization formulations are introduced for the existence of reduced-order filters, and several efficient optimization algorithms of local and global optimization are proposed. Nontrivial and less conservative relaxation techniques are presented as well. The viability and efficiency of the proposed approaches are then illustrated through computational experiments and comparisons with existing methods.

Exploring the Limitations of Behavior Cloning for Autonomous Driving

Abstract: Driving requires reacting to a wide variety of complex environment conditions and agent behaviors. Explicitly modeling each possible scenario is unrealistic. In contrast, imitation learning can, in theory, leverage data from large fleets of human-driven cars. Behavior cloning in particular has been successfully used to learn simple visuomotor policies end-to-end, but scaling to the full spectrum of driving behaviors remains an unsolved problem. In this paper, we propose a new benchmark to experimentally investigate the scalability and limitations of behavior cloning. We show that behavior cloning leads to state-of-the-art results, executing complex lateral and longitudinal maneuvers, even in unseen environments, without being explicitly programmed to do so. However, we confirm some limitations of the behavior cloning approach: some well-known limitations (e.g., dataset bias and overfitting), new generalization issues (e.g., dynamic objects and the lack of a causal modeling), and training instabilities, all requiring further research before behavior cloning can graduate to real-world driving. The code, dataset, benchmark, and agent studied in this paper can be found at \url{github.com/felipecode/coiltraine/blob/master/docs/exploring_limitations.md}

Direct Observation of Hydrogen Molecules Adsorbed onto a Microporous Coordination Polymer

Abstract: design and synthesis of high-performance hydrogenstorage materials. Although the weakest X-ray scattering amplitude of hydrogen made it difficult to determine their structure, we have succeeded in the first direct observation of elusive H2 molecules adsorbed in the nano-channels of a metal-organic porous material by the in situ synchrotron powder diffraction experiment of gas adsorption and by MEM (maximum entropy method)/Rietveld charge-density analysis [4]. The sample used in this study is microporous coordination polymer 1 with a pillared layer structure (CPL-1) with uniform ordered nano-channels of 4 Å × 6 Å. The in situ synchrotron powder diffraction experiment for hydrogen gas adsorption was carried out using the large Debye-Scherrer camera installed at beamline BL02B2. The hydrogen gas was dosed into the capillary sample through a stainless steel tube connected to the gas-handling system. The amount of adsorbed gas was controlled by adjusting the sample temperature under a constant hydrogen gas pressure of 102 kPa. The structure was investigated by MEM/Rietveld analysis [5]. The amount of H2 molecules adsorbed in CPL-1 at 90 K at 102 kPa was determined to be 0.3 molecules per Cu atom from the hydrogen adsorption isotherm. The reliability (R) factors based on the powder profile RWP and the Bragg integrated intensities RI were 2.45% and 3.33%, respectively. The cell parameters for CPL-1 with H2 gas were determined as a = 4.7101(1) Å, b = 20.0289(2) Å, c = 10.7704(1) Å, and β = 95.472(2)° (space group P21/c). The R factor based on the structure factors in the final MEM analysis RF was 1.86%. In the MEM charge density of CPL-1 without H2 molecules shown in Fig. 1(a), only the nano-channel structure was clearly seen and no electron density was observed in the nano-channels, even at lower electron-density levels. On the other hand, in the MEM charge density of CPL-1 with H2 molecules (Fig. 1(b)), the small peak maxima of the electron densities with an elongated shape distribution, which are due to the adsorbed H2 molecules, were observed in the nano-channels. It should be noted that the posit ion and orientation of the H2 molecules are mean values obtained by statistical analysis. The

Oxygen Storage Materials for Automotive Catalysts: Ceria-Zirconia Solid Solutions

Abstract: This paper reviews progress in the development of oxygen storage materials for automotive exhaust catalysts. The research was mainly conducted as a study and development exercise in the author's laboratory in Japan. Ceria-lanthana solid solutions (CL) and the first generation of ceriazirconia solid solutions (CZ) were developed as excellent oxygen storage materials for automotive catalysts in the 1980s. These materials consist of ceria doped with less than 20 mol% of La4+ or Zr4+. An increase in oxygen defects in CL and CZ under reductive conditions is responsible for an enhanced oxygen storage capability on the cerium atoms. An accurate measure of the oxygen storage capacity (OSC) per cerium is very important for theoretical and practical treatments of the catalyst. The term “partial OSC” was introduced to describe this capacity and to differentiate it from the usual definition of the OSC, known also as the “total OSC”. After the development of CL and CZ, a new technology was developed to dissolve more than 20 mol% of zirconia in the ceria, allowing second generation CZ and third generation CZ (known as ACZ, which is doped with alumina) to be successfully developed in the 1990s. The partial OSC of these materials increases with increasing amounts of zirconia dissolved in the ceria, and also with decreasing material particle size after an engine durability test. In the case of ACZ, alumina was added to CZ based on the “diffusion barrier concept”, in which a diffusion barrier layer inhibits the coagulation of CZ and A when the material is required for duty at high temperature in air. Furthermore, the relationship between the total or partial OSC and the structure of the ceriazirconia solid solutions is explained in this paper. For ceriazirconia solid solutions composed of equimolar CeO2 and ZrO2(Ce/Zr=1), the total or partial OSC of the κ-phase CeZrO4, in which the cerium and zirconium ions are regularly distributed, was about twice as large as that of a ceriazirconia solid solution with a relatively irregular distribution of cerium and zirconium ions, and about five times larger than that of a mixture of ceria powder and zirconia containing only a small amount of ceriazirconia solid solution. It corresponds to about 89% of the theoretical maximum value. For a ceriazirconia solid solution composed of non-equimolar CeO2 and ZrO2(Ce/Zr ≠ 1), the partial OSC of a ceria-κ-phase solid solution with a zirconia content of between 30 and 50mol% is much higher than that of a ceriazirconia solid solution of the same zirconia content. The partial OSC of a κ-phase and zirconia mixed oxide, which is formed by reducing the material at 1200 °C, reaches a value above 0.20 mol-O2/mol-Ce (about 80% of the theoretical maximum value of the partial OSC), when the zirconia content is between 50 and 80 mol%. The Toyota Motor Corp. has put automotive three-way catalysts containing the first, second and third generations of CZ into practical use on a global basis.