Innovations in Auto Safety Design, a Key to Quality Improvement

Home , Armrest, Automotive safety, Motor vehicle

KALU UDUMA

ABSTRACT

As the public becomes increasingly aware that safety is a health-related issue, more stringent requirements have now been placed on manufacturers’ products so as to limit injuries to people from these products. Therefore, a product’s quality is now no longer measured solely in terms of aesthetic, comfort, and durability, but increasingly, in terms of its injury mitigating features. In the Auto Industry for example, safety has become the major factor driving the design of new vehicles. Innovative safety concepts are continuously sought after and evolved by safety engineers to forestall crash (crash avoidance design concepts), reduce injury when crash does occur (vehicle crashworthiness), and to protect occupants and pedestrians from flames and other hazards after crash (postcrash protection design concepts). The objective of this paper is to provide a perspective of the evolution of automotive safety in the United States and also take a peek at global future trends. In addition, this paper shows how innovative safety concepts are not only shaping vehicle design but also changing the rigid definition of vehicle quality. Practical examples of evolutions of innovative safety concepts through the processes of Inventive Engineering are presented in the area of vehicle crash engineering. Concepts constraints are briefly reviewed as related to their design contradictions to comfort quality and safety quality. The focus is on Head Injury Criterion (HIC) and Dynamic Side Impact (DSI) regulatory requirements.  2000 Elsevier Science Inc.

Introduction In The United States, Charles E. and J. Frank Duryea are regarded as the ones who pioneered the “motorization” of the traditional horse-powered vehicles, when in 1893, they placed a small internal combustion engine in a modified horse-drawn carriage in Springfield, MA [1]. However, a distinctly motorized vehicle, referred to in the United States as the “automobile,” was first introduced by the French Panhard Company in 1894. Motorization of the American highway system was subsequently enthusiastically embraced because it fitted very well into the highly mobile American culture [1]. No consideration was given to safety of the road system. However, over the years following the introduction of early automobiles, safety designs have, as of necessity, evolved in response to the tragic deaths that motorization brought to the American highway system. This paper will provide a perspective to this safety evolution and also try to predict future auto safety trends. It will also be shown here that auto safety considerations are not only gaining prominence in the shaping of vehicle design, but also redefining the

Address correspondence to K. Uduma, Vehicle Development-Impact Systems, DaimlerChrysler, 800 Chrysler Drive, Auburn Hills, MI 48236-2757.

Technological Forecasting and Social Change 64, 197–208 (2000)  2000 Elsevier Science Inc. All rights reserved. 0040-1625/00/$–see front matter 655 Avenue of the Americas, New York, NY 10010 PII S0040-1625(00)00085-8 198 K. UDUMA rigid deﬁnition of product quality in automotive engineering. The evolution of two innovative safety concepts will be used to describe how the processes of Inventive Engineering can aid in auto product quality.

Evolution of Automotive Safety Automotive design philosophy has progressed from the initial total belief that automobiles are inherently safe products and, therefore, cannot by themselves cause injury, through a token recognition of their culpability in injury causation, to a formal acceptance that safety designs are important attributes to auto product quality through injury mitigation. In the years leading up to the 1920s, auto safety advocates were mostly concerned with road construction and maintenance. In the 1920s, the automotive industry joined hands with other safety advocates to urge the Federal Government to take over from the states, the construction, maintenance, and regulation of the road system. The motive then was to override the conflicting state and local laws, which they felt were inhibiting the sale and use of motor vehicles [1]. In the years between 1920s through the 1930s, there was an increased concern for auto safety because of the increasing number of auto related fatal accidents. Indeed, in 1924, Herbert Hoover, then Secretary of Commerce, is said to have called the first National Conference on Street and Highway Safety [2], which laid the groundwork for uniform motor vehicle laws. However, the pervading thinking then was that a car under normal usage does not cause an accident but that bad driving or a careless driver does. The emphasis to reduce accidents was, therefore, a campaign for increased driver edu- cation. Between the 1930s and the 1940s, a small but effective safety advocacy group had grown [1], mostly among the medical profession, who saw first hand the victims of automotive accidents and their mutilations. From some persistent injury patterns, the doctors related those patterns to specific vehicle designs that they were convinced must be responsible for inflicting such injuries. This probably was the beginning of recognition that automobiles may not be inherently safe products after all, but by design, may have some attributes of being injurious to users. In the years between 1940 to 1950, human emotions and sentiments had combined with the new understanding of the mechanics of injury causation in the automotive, to initiate hearings and introduce auto safety legislation in the Congress. In the years between 1950 to 1960, auto industry representatives were leading the President’s committee on Highway safety [1], and the philosophy of driver responsibility had by now been accepted even by the Government. However, in the 1950s, three Senators, by chance of personal experiences, had become strong auto safety advocates. Senators Paul H. Douglas of Illinois, Margaret Chase Smith of Maine, and congress- man Kenneth A. Roberts of Alabama had, in the early to mid-1950s, introduced various auto safety legislation in the Congress [1]. In the 1960s, Daniel P. Moynihan, then Assistant Secretary of Labor for Policy Planning is said to have invited Ralph Nader to serve as a consultant in highway safety. Nader is said to have brought in a wealth of research knowledge in automotive safety to the Ribicoff committee, which was then working on highway safety. In 1967, after years of legislative hearings and publications, the Department of Transportation enacted the Highway Safety Act and the National Traffic and Motor Vehicle Safety Act (MVSS). This legislation included regulations for accident prevention, injury protection, postacci- INNOVATIONS IN AUTO SAFETY DESIGN 199 dent protection, consumer information, and others intended to protect people and improve vehicle safety [1].

Automotive Safety and Styling: A Paradigm Shift J. C. Furnas’s “And Sudden Death” [3] did not only help to explain the mechanics of injury causation during a vehicle accident, it went further to illustrate the dangers inherent in the design of vehicle interiors. Furnas pointed out that passengers were injured by splinters from the wooden parts of the body, by ﬂying glass, or sometimes “instantly killed by shattering their skulls on the dashboard” [3]. He went on to paint a lurid but accurate picture of injury causation: “The driver is death’s favorite target. If the steering wheel holds together it ruptures his lever or spleen so he bleeds to death instantly. Or, if the steering wheel breaks off, the matter is settled instantly by the steering column’s plunging through his abdomen” [3]. To date, the vehicle interior’s dual role as both a comfort cabin and a safety cage continues to dominate design decisions of new vehicles. Unfortunately, there are conﬂicting constraints satisfactions in trying to meet both quality requirements. Design- ers and Safety Engineers are each continually contesting for priority of each role. However, as the public becomes increasingly aware of the huge cost of auto-related injury, greater demands and emphasis are now being placed on vehicle safety. Indeed, there is now a paradigm shift from vehicle design for aesthetic to a design for safety. New vehicles are not launched until all impact-related safety requirements are met. Yet, styling and safety need to blend together to produce a total quality vehicle. Innova- tion through inventiveness may be the only process through which this blending can be achieved.

Safety Concepts and Inventive Engineering Designing to meet the new requirements of the Federal Motor Vehicle Safety Standard (FMVSS) #201, is one area in which this blending is being tested. The amend- ment to FMVSS 201 now includes head impact protection in the areas above the vehicle belt line of interior components such as the headers, roof, roof rails, and pillars. The new rule took effect in the 1999 model year. To meet this new rule, energy-absorbing countermeasures such as foams or plastic trims with structural ribs must be designed onto the suspected hard surface of these interior structures. The energy absorber concept shown in Figure 1, for example, evolved through the application of the fundamental methodological processes of Inventive Engineering. Fundamental Methodological issues of Inventive Engineering deal with innovation in design [4], including: (a) general models of the design process, (b) integration of various design methods and tools, (c) evolution of design processes, and (d) novelty/innovation and its formal measures. A structural column model was used in this instance. Its response to impact loading, through axial crush and lateral bending to absorb the kinetic energy of impact, was integrated into the traditional “hard” plastic trim to form a “ribbed” structural plastic energy absorber. Parameter studies were then conducted to identify the optimum rib height (h), rib thickness (t), rib spacing (d) to avoid stack-up and rib material modulus (E) to establish the design processes for this new product. The measurable of this product is the amount of kinetic energy of the head impact absorbed to decelerate the head and reduce HIC. Therefore, Fundamental Methodology process of Inventive Engineering can be followed to blend the traditionally decorative plastic trim cover into an innovative safety product for head-injury reduction during a vehicle crash. Current understanding requires 25 millimeters of crush space to package the energy- 200 K. UDUMA Fig. 1. Plastic trim cover with structural ribs. INNOVATIONS IN AUTO SAFETY DESIGN 201 absorbing countermeasure [5]. This crush space applies to both thermoplastic trims and foams. With current rib technology, any head-injury criterion (HIC) above 1,000 needs to be reduced by packaging at least 25 millimeters of an energy absorber. Figure 1 illustrates a typical A-pillar ribbed plastic trim countermeasure design. Figure 2 is another innovative countermeasure design applicable in a “confined environment” [5] (with a crush space less than 12 millimeters). In this case, the crush space is too small for the amount of kinetic energy to be absorbed, using one-dimensional structural elements. A surface element, such as a shell, becomes the optional model to initiate the Fundamental Methodology of Inventive Engineering. The remaining processes of this methodology were completed to evolve the new product shown in Figure 2. Figure 3 shows the energy management effectiveness of this innovative countermeasure compared to the traditional design. In Figure 3, the vertical axis (G, represents the ratio of the head acceleration to the acceleration due to gravity. It is, therefore, a dimensionless quantity. The horizontal axis, in inches, represents the combined local head skin deformation, the deformation of the Bathtub bracket, the local indentation of the B-Pillar, and the global motion of the B-Pillar. Notice the similarity, as should be expected, of the response at the left and right B-Pillars. The apparent difference is only a phase shift from the post pro- cessing utility. After frontal impacts, side impacts are the second most common type of collision to cause serious or fatal injuries (AIS 3-6) [6]. Satisfying the safety requirements during side collisions (Side Impact regulatory safety criterion, FMVSS 214), is, therefore, another area where styling must give in or at least accommodate the design requirements for safety. Limiting the impact force on the occupant’s abdomen and the amount of rib deformation, for example, are some of the criteria that the European side impact requirement must satisfy. Field data of actual vehicle accidents have demonstrated that contact of a stiff armrest with the abdomen, concentrates load on the abdomen, inducing force levels in excess of the safety requirement. Figure 4 shows the armrest crushing onto the dummy abdomen after impact. Figure 5 shows why this armrest area of the vehicle interior, needed a redesign to present the occupant with a spread out rather than a concentrated force. Here again, styling and safety were in collision course, but to launch the new vehicle, styling and the needs for safety design had to find a common ground. Physical test simulations of a side impacted vehicle show that most B-Pillars buckle at the midlength, from the roof rail to the sill. This local kink concentrates loads through the door onto the occupant’s rib cage, causing excessive rib deformation. To prevent this local kink of the B-Pillar, the Methodics processes of Inventive Engineering was combined with the Fundamental Methodolgy to evolve an innovative safety product. Methodics subjects of Inventive Engineering are concerned with [4] the study of innovation oriented design methods, including their development, mathematical modeling, and experimental verification. Rather than rigidly connect the B-Pillar at both ends, two “hinges” were induced at selected portions of the B-Pillar, such that the portion in between these two hinges translated uniformly upon impact, thereby, presenting a more friendly loading surface to the occupant [7]. Finite element models and simulations of the hinge action were initially conducted, and a physical test to verify the hinge concept was conducted to evolve the hinge initiator, shown in Figures 6 and 7. 202 K. UDUMA Fig. 2. Headform impact on an innovative energy absorber bracket. INNOVATIONS IN AUTO SAFETY DESIGN 203 Fig. 3. Energy management comparison, ribbed plastic trim versus innovative design. 204 K. UDUMA Fig. 4. Armrest crush on dummy abdomen, before and after impact. INNOVATIONS IN AUTO SAFETY DESIGN 205

Fig. 5. Door interior trim at armrest needing a redesign.

Automotive Safety: A Redeﬁnition of Vehicle Quality The history of the early automotive design was based initially on a philosophy that emphasized styling rather than safety function. At that early period, vehicle power, speed, size, and even psychological factors, came to serve as symbols of qualities of the vehicle [1]. Today’s passenger cars and trucks are, as in the early days, started in the design (essentially, styling) department. However, because the Department of Transportation enacted the Highway Safety Act and the National Trafﬁc and Motor Vehicle Safety Act (MVSS), today’s model year vehicles must meet all the safety regulatory requirements to be launched. Indeed, safety recalls are initiated by individual auto companies to forestall otherwise costly litigation and expensive court awards to injured victims. Today’s auto companies advertise safety gadgets and features in new vehicles more readily than bodily appearances. In fact, a major attraction of utility vehicles is not merely for 206 K. UDUMA

Fig. 6. Hinge initiator bracket.

roominess, but more for their perceived ruggedness and safety. In today’s deﬁnition, vehicle quality has become intertwined with and synonymous to vehicle safety, style, durability, and comfort. Safety has, in effect, become the major factor driving the design of new vehicles.

Future Trends in Auto Safety Safety regulations and countermeasure designs will continue to evolve as the Gov- ernment tries to cut down on the huge costs of auto-related accidents and auto companies feel the pinch of product liability. One does not need to be clairvoyant with respect to future safety demands in the auto industry. Clues as to the safety trend of the future may be found in the National Highway Trafﬁc Safety Administration’s (NHTSA) research programs. NHTSA’s latest short-term research mission is stated as follows [8]: “in the next ﬁve-year period NHTSA will continue research to increase the understanding of system performance levels for collision avoidance (CA) products and systems.” Despite this short-term goal statement, it is conceivable to forecast that research activities will be spread out in the areas: Environment, Crash Avoidance, Crashworthiness, Biomechanics and Trauma. With these in mind, the most probable research activities will be in the areas of [8]: (a) Electric and Alternative Fuel Vehicle Safety—electric vehicles and alternative fuels, such as liquid hydrogen are expected to help reduce environmental pollution; and (b) Intelligent Vehicle Systems (IVHS). These include but are not limited to: INNOVATIONS IN AUTO SAFETY DESIGN 207

Fig. 7. B-Pillar/hinge initiator and B-pillar hinge action.

1. Navigation Systems—these systems are touted as safety devices for travelers so they can concentrate on driving instead of watching for street signs and route numbers. 2. Drowsy Driver Warning Systems—these are systems that can detect driver erratic movements and sound alarm or ﬂash lights to awaken the driver. 3. Crash Avoidance Systems— 4. Intelligent Cruise Control—intelligent cruise control will adapt to the leading cars’ speed and resume the desired speed when there is adequate headway. These are used to alert drivers of inadequate headway. 208 K. UDUMA

5. Blind Spot Detection System—ultrasonic, infrared (IR), and radar systems will warn drivers of vehicles in the blind spots of their mirrors. 6. Collision Avoidance Automatic Breaking—near-object detection systems will warn of objects below the sight line such as children, toys, posts, and walls. 7. Lane Guidance—infrared night vision systems are being evaluated too, which may become particularly valuable to aging drivers. 8. Vehicle Aggressivity and Fleet Compatibility—this will explore the potential for reducing injuries by eliminating incompatibilities, both structural and geometric, between passenger vehicles and their potential collision partners. 9. Anatomic Development—develop advanced material and ﬁnite element models to better characterize the response of the dummy components and biological tissues used in the study of injury mechanics in vehicular accidents.

Conclusion Safety design consideration in the automotive industry has evolved from a miniature status in vehicle quality definition to a major factor that shapes the design of new vehicles. Innovative safety concepts are not only as of necessity, evolved to meet safety regulations, but also to fit into the new and increasing consumer definition of total vehicle quality. Safety quality and comfort quality, more often than not, present to the stylist and the safety engineer contradicting design constraint satisfactions. However, for any automotive company to survive, and indeed thrive in the fierce competitive market environment, style and safety design attributes must be blended to produce a total vehicle quality. The processes of Inventive Engineering are the logical steps through which this blending can be achieved. These processes have been followed to evolve two safety concepts for head injury reduction during a vehicle crash. The processes have also been followed to evolve a concept that shapes the profile of an intruding B-Pillar into a more friendly surface when it makes contact with the occupant during impact. Future trends in auto safety may be found in the research activities of NHTSA. These safety activities will rely more on intelligent systems, especially as Information Technology becomes more widespread. Both comfort quality and safety quality will invariably rely on this new technology for the much needed blending.

References 1. Eastman J. W.: Safety vs. Styling: The American Automotive Industry and the Development of Automotive Safety, 1900–1966, Lanham, MD: University Press of America, Inc., 1984. 2. Washington Conference on Street and Highway Safety. First National Conference on Street and Highway Safety, Washington, DC, December 15–16, 1924, p. 38. 3. Furnas, J. C.: And Sudden Death, Reader’s Digest Aug. 21–26 (1935). 4. Arciszewski, T.: Inventive Engineering: From Theory to Practice (internal publication). George Mason University, Fairfax, VA, 1998. 5. Uduma, K., Mugford, D., and O’Brien, R.: BathTub Bracket—An Efﬁcient Energy Management Bracket for HIC Reduction in a Conﬁned Space, DaimlerChrysler U.S. patent application, 1998. 6. Notice of Proposed Rulemaking, NHTSA Aug., 62(165), 45202–45216 (1997). 7. Hobbs, C. A.: Dispelling the Misconceptions about Side Impact Protection. SAE Technical Report, No., 950879, 1995. 8. Project Summaries NHTSA.: Research and Development. NetScape.

Received 14 March 1999; revised 30 October 1999; accepted 1 February 2000