Recently, most of new products are realized as improvement design, which is characterized by rather limited changes to past generation products. By reusing verified and experienced components of the past, design of new product can be accelerated and reliable. However, some products increasingly become so complex that changes to some components propagates unpredicted changes to other components. Due to the unpredicted changes, it becomes more difficult for companies to benefit from the advantages of improvement design. Lack of holistic understanding of product leads to unpredicted propagation of changes and causes delay and budget overrun. Therefore, a change plan should be preliminary deliberated before the embodiment design is initiated. This paper proposes a design planning method for improvement design based on extended house of quality, which is employed in quality-function-deployment. In the proposed method, design solutions are evaluated in two aspects; opportuneness and drawback risk. Change planning is dealt as to determine parts to be redesigned in the tradeoff between opportuneness and drawback risk. A case study on a design of a solar boat demonstrates the application of the proposed method and verified its validity.

In recent years, the CMMs (Coordinate Measuring Machines) quickly have been spreading over the manufacturing industry. Under the circumstances, the environmental conditions and installation sites of CMMs have been changed from the temperature control room to the workshop environment and the production line without air conditioning. However, even in severe environment the demand to high accuracy measurements by CMM has been increasing still more. Thereby, the methods to evaluate and realize the high accuracy measurements by CMM in workshop environment have been investigated. In this paper, we clarify the factor of scale error and propose the effect and correction method of temperature measurement errors using scale error of CBG (Low-expansion Ceramics Gauge Block) and MBG (Metal Gauge Block). The scale error can be reduced by installing thermometers for temperature correction at optimum positions and increasing the accuracy of the thermometers. Compared with MBG, CBG was able to confirm that the scale error of CMM can be evaluated without being affected by temperature change of workpiece. Additionally, the performances of the adiabatic material are tested and confirmed experimentally.

Quadruped robots are expected to use on a terrain with high undulation, especially a high step. This paper describes a design concept and practical method to decide a leg parameter to overcome relatively higher steps to the robot size. The situations of front and rear leg are different in the case of stepping from lower ground to the higher step, avoiding a collision of leg and the step. Front shin should be almost vertical when it is on the lower ground, but can be up to almost horizontal to reach its foot to the step. Contrary, rear shin should be kept vertical during a swing from lower ground to the higher step. Thus, the required vertical movable range of thigh is different. The front thigh can be designed with additional shin length, but rear thigh should have its own movable range of overcoming step height. Introducing a new concept of cross leg configuration, where front leg roots the rear end of body and rear leg roots the front end of body, the whole robot can be designed small relative to the length of leg linkage. Equipping mecanum wheels on each foot, the machine can move omnidirectionally without sideways motion of leg linkage, and become stiffer and lighter. All these concepts are verified by a manufactured robot with the size of overcoming 700mm steps.

The cavitation around a butterfly valve occurs because of the large flow separation behind the valve body and the interference of the flow from the nozzle side and the flow from the orifice side. To avoid this cavitation, the installation of perforated plates behind the valve are proposed in this study. From the experimental results, the cavitation noise can be reduced by the perforated plates. It was confirmed by the numerical analysis that the holes of the plates were helpful for pressure recovery behind the valve body. Butterfly valves are widely used in industry because of their compactness and simple construction. Many kinds of anti-cavitation valves have been proposed, however, those are relatively expensive and the structures are complicated. The installations of perforated plates are very easy and very effective in practical use.