Development Story 04
Two new features were added to the conventional "Dig Nav". The one is the "level-ground assist function" that allows precise operation in accordance with design simply by operating the arm levers. The other is an "over-digging prevention function" that allows construction without harming the design. The machine control system enables anybody to enjoy the knowhow of an expert.
To make up for the labor shortage at construction sites, the Ministry of Land, Infrastructure, Transport and Tourism is proposing the promotion of "information-oriented construction" that uses information and communication technology (ICT). In response, in 2005, KOBELCO introduced its "Dig Nav" machine guidance system for navigating the digging operations of excavators, using display screens and alarms as well as positional information.
This time, KOBELCO announced its "Dig Nav +PLUS" 3D machine control system. This is a system that provides the operator with the expert ability to precisely replicate the complex movements of the excavator with just the arm lever controls. As the system allows precise operations in accordance with design, a rookie operator can produce high productivity and precision of a veteran. The system is paid attention to as a significant boon to any construction site.
In the first place, the thinking behind "information-oriented construction" is to inherit the skill of an expert as the aging of the population progresses, while handling the work with a less number of individuals and exceeding the efficiency and precision of jobs. For example, tasks like shaping the face of a slope using an excavator require a high level of skill and precision to create a smooth surface. Yusuke Kamimura, who helped drive this project, had this to say.
The fundamental concept of “Dig Nav +PLUS” is to allow a link of complex control actions using the boom, arm and bucket - a high level of expert skills - to be controlled simply by levers. That is the machine assists the operator for the skills of an expert, just with a few simple controls.
To accomplish this, KOBELCO collaborated with Trimble Inc., the world's eminent manufacturer of measurement equipment. Both parties combined their strengths to realize this system.
The actual development began in August 2016. Working with Trimble Inc.'s development team, the project progressed both in Hiroshima and New Zealand at the same time. The firm cooperation between the experts of both companies brought about the verification of an actual device in New Zealand in March 2017. By May, the team began ordering parts in preparation for mass production. It was a tough schedule, but they managed to pull it off.
Together with Kamimura, Yuki Kojima went to New Zealand to help advance the development project. According to Kojima, "Our passion as engineers helpled overcome any culture or language barriers."
To modify the actual machine, we demonstrated the wiring and piping to deepen our mutual understanding and convey whatever we couldn't communicate with words. There was actual feeling of "let’s create an excellent product" that mutually existed in our engineer spirit.
Masaru Numasawa, belonging to the Quality Assurance Dept., emphasizes that the precision improvement for "Dig Nav +PLUS" was accelerated by checking the system from a user's standpoint and focusing on the replication of on-site knowhow.
We had veteran operators, with over 20 years of on-site experience, test-drive our products and we reflected their impressions in our development. That is because we feel that it is important to apply the viewpoint of the market including usability and specification requirements, in addition to structure, rigidity and mechanism viewed from the manufacturer's side.
We also investigated the most suitable values such as the movement speed of various areas and the response between lever operations and actual movement. For the speed of simple movements, we could mechanically speed them up. But the speed required for improving work efficiency during an actual task is what only an operator fully acquainted with the operation would know. Therefore, we asked our customers who are actively engaged in construction work nationwide to provide us with monitoring evaluation.
We focused on gathering the fair opinion of a wide range of users who have operated our machine. That meant customers who had an experience of ICT construction machinery operation or not, as well as experienced veterans and rookie operators.
A survey taken after test-driving of the machine resulted in several evaluations such as "I was surprised by the operating speed" and "I could move the machine just the way I wanted to". There was even a comment that said, "We convinced the immediate effectiveness of a rookie and more performance efficiency brought out by a veteran. This is a machine that improves on-site productivity."
Naoki Goto, who participated in this project as an expert in electronic control, focused on collecting the demands of both Trimble Inc. and KOBELCO as well as the operators to realize concrete functions.
We analyzed the data of a veteran operator who actually held the controls. We measured the speed of each action and the response from activating the control levers up to the actual movement. We took this information and made it possible for anybody to use the software’s system to replicate the expert’s moves.
With this project, we had already the participation from the manufacturing section at the conceptual stage before the prototype was manufactured. From the upstream process of development, we reflected the opinions of the factory side to eliminate the unnecessary returns in the downstream process. As a result, we were able to establish a mass production system very quickly.
"Dig Nav +PLUS" was completed across the Pacific and taking in information from people other than the development leaders. It should contribute as a new solution to construction site issues such as labor shortage and skill succession.
* The contents described above is based on the information at the time of issuing (January, 2018).